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The decline of moths in Great Britain: a review of possible causes
Abstract
1. Population declines among insects are inadequately quantified, yet of vital importance to national and global biodiversity assessments and have significant implications for ecosystem services.
2. Substantial declines in abundance and distribution have been reported recently within a species-rich insect taxon, macro-moths, in Great Britain and other European countries. These declines are of concern because moths are important primary consumers and prey items for a wide range of other taxa, as well as contributing to ecosystem services such as pollination.
3. I summarise these declines and review potential drivers of change. Direct evidence for causes of moth declines is extremely limited, but correlative studies and extrapolation from closely related taxa suggest that habitat degradation (particularly because of agricultural intensification and changing silviculture) and climate change are likely to be major drivers. There is currently little evidence of negative population-level effects on moths caused by chemical or light pollution, non-native species or direct exploitation.
4. I make suggestions for future research with a focus on quantifying impacts of land management practices, light pollution and climate change on moth population dynamics and developing evidence-based measures that can be incorporated into agri-environment schemes and other policy initiatives to help reverse the widespread decline of moths in Great Britain and beyond.
... Trots mångfalden av nattaktiva organismer är det bara ett fåtal som utför pollineringstjänster, av dem är insekter de viktigaste (Borges, 2018). För pollinering av blommor anses nattfjärilar vara viktigast efter bin och humlor (Fox, 2013;Macgregor m.fl., 2015). Det har konstaterats en oroande minskning av insektsarter, särskilt flygande insekter (Eggleton, 2020) och makromalar i Europa (Fox, 2013). ...
... För pollinering av blommor anses nattfjärilar vara viktigast efter bin och humlor (Fox, 2013;Macgregor m.fl., 2015). Det har konstaterats en oroande minskning av insektsarter, särskilt flygande insekter (Eggleton, 2020) och makromalar i Europa (Fox, 2013). Utomhusbelysning kan orsaka direkt dödlighet och har störande effekter på nattfjärilars beteende och livscykler (Fox, 2013). ...
... Det har konstaterats en oroande minskning av insektsarter, särskilt flygande insekter (Eggleton, 2020) och makromalar i Europa (Fox, 2013). Utomhusbelysning kan orsaka direkt dödlighet och har störande effekter på nattfjärilars beteende och livscykler (Fox, 2013). Oro påpekades då nattfjärilar är viktiga primärkonsumenter och bytesdjur för många andra arter. ...
Outdoor artificial light at night (ALAN) is raising concern as a possible cause of the loss of insect diversity. Due to a diurnal bias in standard methods in environmental monitoring and urban ecosystem service assessments, the issue has remained in the dark and especially relevant for nocturnal pollination, which is less well known. This umbrella review analyses the effects of light pollution on pollination services at night through a cascade framework. The report aims to gather understanding of the state of scientific knowledge to date of the combined interdisciplinary field of pollination, ecosystem services and light pollution. Findings show that outdoor lighting works as barriers and habitat fragmentation for nocturnal pollinators reducing flower visitation and pollen transport affecting plant reproduction. Integrating the understanding of stressors of light pollution and the benefits of darkness into urban land use planning have the possibility of improving the abilities of pollination services in a nightscape usually overlooked. Case studies on the benefits of darkness in the management of urban ecosystem services are of interest in future studies together with the mapping on the values of nocturnal pollination networks.
(available only in Swedish) Link to full text: http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-47191
... Ztráta biotopu je známý faktor ohrožující denní motýly v Evropě , Wenzel et al. 2006, Hanski & Poyry 2007, Ockinger et al. 2010. Předpokládá se, že na společenstva můr bude mít podobný dopad (Fox et al. 2013). Ztráta biotopů nastala především intenzifikací zemědělství a koncem tradičního hospodaření, došlo k homogenizaci krajiny. ...
... Conrad et al. (2004) zaznamenal ve Velké Británii negativní trend populací můr vázaných na listnaté lesy, a naopak nárůst populací druhů vázaných na jehličnaté stromy. Obnovení managementu je vhodné pro celkové zvýšení biodiverzity (Šebek et al. 2015) a zvýší diverzitu můr na větším prostorovém měřítku (Fox et al. 2013), přičemž můry mohou reagovat se zpožděním a vliv otevření stanoviště se na diverzitě objeví až po několika letech (Bolz 2008). Nicméně na druhou stranu není vhodné otevírat staré ustanovené lesní porosty. ...
Metodika zahrnuje všechny přírodní biotopy v České republice a věnuje se péči o ohrožené zástupce jak nočních, tak denních motýlů. Naopak všechny předchozí studie se omezovaly jen na stanoviště lesní nebo nelesní, případně motýly denní nebo noční.
Vedle důkladné znalosti relevantní literatury používá Metodika údaje o početnosti, stanovištní vazbě a nárocích na péči jednotlivých druhů získané z obrovských objemů dat, shromážděných pro denní motýly, a pro tzv. „malé čeledi“ motýlů nočních, v databázi „Mapování motýlů České republiky“. Na sběru dat se podílejí ročně stovky amatérů i profesionálů. S nejaktivnějšími z nich autoři konzultovali stanovištní nároky druhů, navíc lokality prakticky všech ohrožených druhů byly navštíveny v roce zpracování Metodiky a nároky ohrožených druhů upřesněny. Novátorská je analýza příčin ohrožení, konfrontující moderní poznatky o ohrožení denních a nočních motýlů, stejně jako přístup k jednotlivým typům stanovišť, které jsou pojímány spíš podle celkové fysiognomie vegetačního krytu než podle druhového složení. Vedle standardních zemědělských (seč, pastva) a lesnických (prosvětlování korunového patra, pěstování nízkých a středních lesů) doporučení obsahuje metodika i diskusi k perspektivním přístupům – radikálnějšímu mechanickému managementu a volné pastvě velkých herbivorů, která je slibnou alternativou pro velká a různorodá území.
... Так, стан їх популяцій в певні періоди можна охарактеризувати як депресивний, але в інші -відзначається різке зростання чисельності [1,6]. Деякі види шкідників повністю втрачають свою актуальність, проте їм на зміну з'являються інші [30,32,33]. Досить часто такі різкі збільшення чисельності фітофагів, так звані «спалахи», все ще залишаються для аграріїв стихійним лихом і важко передбачувані [34][35][36][37]. ...
... У свою чергу все це призводить до змін екологічного оптимуму різних видів шкідників [3,4]. Так, зміни клімату впливають на зміни ареалу багатьох фітофагів та зон їх шкідливості [11,25,33,34,37]. Як приклад тому, на сьогодні більшість переважно степових видів стають звичними і в непритаманних для них Лісостепу та навіть на Поліссі [3, 10, 12-14]. ...
... Also, biomagnifications and bioaccumulation pose added threats to insect survival as well as their physiology and behavior (Hayes & Hansen, 2017). Similarly, harmful effects were also induced by fertilizers indirectly by disturbing the composition or the quality of the plant resources, soil acidification, and eutrophication (Fox, 2013;Villalobos-Jim enez et al., 2016). High doses of fertilizers might benefit a few insects i.e. aphids (Kyt€ o et al., 1996) but otherwise, they harmed most of the insects generally (Habel et al., 2019;Kurze et al., 2018). ...
... Neonicotinoid residues found in pollen and nectar are consumed by flower-visiting insects such as bees and these could cause sub-lethal effects on them through various application practices such as soil application, (the residues could persist longer even after a single application) and seed coating and may reach the lethal levels (Fox, 2013;Qi et al., 2020). Even the untreated plants could absorb the residues from the previous year. ...
ABSTRACT
Insect pollination establishes an ecosystem service around the globe, providing compelling
budgetary and creative profits along with developmental values to humans and vital eco�friendly measures for the environment. It is, therefore, essential to understand how insect
pollinator populations and communities respond to rapidly changing environments if we are
to maintain healthy and effective pollinator services. Although insect pollinators are known
to provide ecosystem services to more than 80% of the world’s flowering plants (including
cultivated crops), a steep decline (�20–40%) in their population has created an alarming
situation for global biodiversity. Threats to bee populations in recent years have increased
awareness about the critical role of pollinators for life on earth, as pollinators are predicted
to persist only when all animal-pollinated plant species persist. Additionally, increased usage
of chemical pesticides may result in the collapse of pollinators which leads to a decrease in
food resource density and also facilitates the increasing isolation of natural habitats. So, to
overcome pollinators’ decline, joint efforts of all stakeholders are needed to increase their
numbers on the planet. We have to cut down the use of synthetic pesticides, ban highly
toxic pesticides, tackle problems related to colony collapse disorder (CCD), climate change,
habitat loss and provide much-needed help to the native pollinator species to revive their
natural habitats. So, this paper aims to focus on appreciating the services of insect pollina�tors and rescuing them from the threats leading to their extinctions which in turn will help
in enhancing global food production
... of scales, is often implicated in falling insect numbers (Fox, 2013;Habel, Samways, et al., 2019;Leather, 2018;Sánchez-Bayo & Wyckhuys, 2019). A key local driver has been heavy herbicide and insecticide applications associated with agricultural intensification (Habel, Ulrich, et al., 2019). ...
... More broadly, our results are consistent with other recent analyses of large-scale insect data that have also revealed complex and heterogeneous spatiotemporal patterns of insect decline. For example, a warming climate in Europe is shifting some moth ranges northward, with species unable to do so declining, but leading to a net range increase overall (Fox et al., 2021). Similarly, recent drops in UK moths seem modest relative to increases seen over prior decades (Macgregor et al., 2019), leading to no net change over time. ...
Many insects are in clear decline, with monarch butterflies (Danaus plexippus) drawing particular attention as a flagship species. It is well documented that, among migratory populations, numbers of overwintering monarchs have been falling across several decades, but trends among breeding monarchs are less clear. Here, we compile >135,000 monarch observations between 1993 and 2018 from the North American Butterfly Association's annual butterfly count to examine spatiotemporal patterns and potential drivers of adult monarch relative abundance trends across the entire breeding range in eastern and western North America. While the data revealed declines at some sites, particularly the US Northeast and parts of the Midwest, numbers in other areas, notably the US Southeast and Northwest, were unchanged or increasing, yielding a slightly positive overall trend across the species range. Negative impacts of agricultural glyphosate use appeared to be counterbalanced by positive effects of annual temperature, particularly in the US Midwest. Overall, our results suggest that population growth in summer is compensating for losses during the winter and that changing environmental variables have offsetting effects on mortality and/or reproduction. We suggest that density-dependent reproductive compensation when lower numbers arrive each spring is currently able to maintain relatively stable breeding monarch numbers. However, we caution against complacency since accelerating climate change may bring growing threats. In addition, increases of summer monarchs in some regions, especially in California and in the south, may reflect replacement of migratory with resident populations. Nonetheless, it is perhaps reassuring that ubiquitous downward trends in summer monarch abundance are not evident.
... Changes to insect abundance and diversity have received much attention lately, with many studies reporting declines at both local and national scales in recent decades (Leather, 2017;Wagner, 2020), although some studies have found overall stability or increase in some groups and regions (Crossley et al., 2020;van Klink et al., 2020). Key drivers of insect decline are thought to be habitat loss, degradation and agricultural intensification (Fox, 2013;Wagner et al., 2021), with growing recognition of the role of light pollution in nocturnally active insects (Owens et al., 2019). In addition, the effects of recent climate change are complex and vary spatially and across species (Menéndez, 2007;Wilson & Fox, 2020), with positive (Fox et al., 2014;Warren et al., 2001), negative (Halsch et al., 2021;Salcido et al., 2020) and in some cases catastrophic (Janzen & Hallwachs, 2021) effects reported. ...
... Agricultural intensification is often cited as a critical driver of insect decline (Fox, 2013;Fox et al., 2021;Wagner et al., 2021) and some studies comparing trends in agricultural and non-agricultural settings have found evidence to support this (Forister et al., 2010;Seibold et al., 2019). However, data on British moths suggest that declines in abundance and biomass since the late 1960s have been more severe in woodlands than in farmland Macgregor et al., 2019) despite a net gain in extent of broadleaf woodland over the same time period; this finding warrants further investigation and is the topic of this article. ...
While agricultural intensification and habitat loss are cited as key drivers of moth decline, these alone cannot explain declines observed in UK woodlands - a habitat that has expanded in area since 1968.We quantified how moth communities changed across habitats and regions and determined how species traits interacted with habitat in predicting moth abundance change. We hypothesised that, in woodlands, species more vulnerable to shading and browsing by deer (species specialising on forbs, shrubs and shade-intolerant plants) had declined more severely than other species, and that moth decline in woodlands was more severe at sites more susceptible to deer damage.We modelled abundance, biomass, species richness and diversity from 1968 to 2016 and explored how these interacted with habitat and region. We also modelled the interaction between habitat and two moth species traits: larval feeding guild and shade-tolerance of hostplant.Moth declines were consistently highest in broadleaf woodland. Abundance, biomass, species richness and diversity declined significantly by -51%, -52%, -14% and -15% in woodlands, respectively, compared to national trends of -34%, -39%, -1% (non-significant) and +10%. Declines were no greater in woodlands more susceptible to deer browsing damage. Traits based analysis found no evidence that shading and intensive browsing by deer explained moth declines in woodland.Moth decline was more severe in broadleaf woodlands than in intensively managed farmlands. We found no evidence that deer browsing or increased shading has driven these trends: the primary cause of the decline of moths in woodlands remains unclear.
... Insects performed three natural processes, which are essential for the proper functioning of the ecosystem. These are pollination of fruit blossoms, decomposition of organic matter into humus, and natural pest regulation (Figure 1) [3,14,15]. ...
... Destruction of insect habitat, agricultural intensification, urbanization, invasive species, agro-chemical pollution, and climate warming are the main causes of global insect declines and loss of biodiversity [4,14,21]. Climate warming is important in the tropics; however, it may have a limited impact on the number of species in temperate regions [4]. Agricultural intensification, urbanization, deforestation, and pesticide pollution account for about 78.7% of the decline causes, while other drivers such as invasive species, climate warming, and other pollutants account collectively for only 21.3% [4]. ...
Organic farming encourages maximum utilization of the natural biological processes to manage the farm in terms of soil fertilization and pest control, which implies using none or less synthetic fertilizers, pesticides, and plant and animal growth-promoting substances. All these practices increase arthropod diversity, particularly soil-dwelling insects. Intercropping, cover crops, and hedges, which are common practices in organic fields, provide alternative habitats for arthropod communities. The refugia also provide a good source of food for pollinators in terms of pollen grains and nectar. The interactions among the different plant and animal taxa (weeds, birds, mammals) that are found in the organic farming ecosystem have a great impact on insects' abundance and diversity. This chapter summarizes the impacts of the organic farming system on the abundance and diversity of insects. The role of organic farming in mitigating the impact of agriculture intensification, urbanization, deforestation, and climate change on global insects' decline and diversity loss is discussed.
... Auswirkungen auf Bestäuber sind in diesem Zusammenhang am besten untersucht, weil sie eine wirtschaftlich bedeutsame Rolle spielen (Potts et al. 2016 Settele et al. 2009;Potts et al. 2010;Storkey et al. 2012;Meyer et al. 2013 Hocheffiziente Feldwirtschaft und Umwandlung von Grünland in Ackerland ("Grünlandumbruch") Zunehmende Schlaggrößen (Flurbereinigung), geringe Feldfruchtdiversität, Strukturarmut, zunehmende Synchronisierung der Ernte, kaum Ruhezeiten (Anbau von Winterweizen) Ackerland ist wegen häufiger und intensiver Eingriffe heute für Insekten als Lebensraum nahezu bedeutungslos; starker Rückgang bei Offenland-Arten durch Verlust von nährstoffarmen, extensiv genutzten Weiden Fox 2013;Thomas 2016;Shortall et al. 2009;Streitberger et al. 2018 Flurbereinigung und Anlage großflächiger Monokulturen Schwund kleinerer Parzellen, einheitlichere Bewirtschaftung, Beseitigung von Strukturelementen (z. B. Hecken, Feldgehölze, Kleingewässer), Homogenisierung der Landschaft Ackerland ist wegen häufiger und intensiver Eingriffe heute für Insekten kaum noch als Lebensraum relevant Goulson et al. 2008;Settele et al. 2009;Diacon-Bolli et al. 2012;Leuschner et al. 2014 Umwandlung von Grünland in andere Landnutzungsformen (Melis et al. 2010). ...
Der vorliegende Bericht stellt Ursachen für die Veränderungen der Insektenfauna zusammen. Daraus werden Vorschläge für Maßnahmen in Sachsen abgeleitet und diese inhaltlich sowie räumlich priorisiert. Die Autoren schaffen mit dem Bericht wissenschaftliche Grundlagen und geben Empfehlungen zur weiteren Umsetzung des sächsischen Handlungskonzepts Insektenvielfalt.
Der Bericht richtet sich an alle Akteure des Naturschutzes und der Landbewirtschaftung.
- English -
The present report compiles causes for the changes in the insect fauna. From this, proposals for measures in Saxony are derived and these are prioritized in terms of content as well as space. With the report, the authors create a scientific basis and give recommendations for further implementation of a concept for insect diversity in Saxony.
The report is addressed to all actors in nature conservation and land management.
... Insects experience stressors from many directions (Wagner et al., 2021), be it the fragmentation, degradation, and destruction of habitats (Fabienne Harris & Johnson, 2004), the enhanced use of pesticides (Hoffmann et al., 2010), invasive species (Madjidian et al., 2008), new diseases (Le Conte et al., 2010) or the effects of climate change in general. All these factors have led to a decline in the diversity and biomass of flying insects (Fox, 2013;Hallmann et al., 2017;Potts et al., 2010). This is not only a problem for the insect populations themselves but also for all species that interact with them, either antagonistically or mutualistically. ...
The interplay between ecological and evolutionary dynamics can create feedback that reinforces external disturbances and potentially threatens species' coexistence. For example, plants might invest less into attracting insect pollinators (decreased flower or nectar production) and more into independence (increased selfing or vegetative reproduction) when faced with pollinator decline. This adaptive response saves plant resources at the cost of further threatening the pollinator population. We ask under which conditions such self-reinforcing feedback occurs in two-species mutualistic systems when considering one-sided population decline and whether it can be counteracted by self-dampening feedback if co-evolution of both interaction partners is considered. Based on a mathematical model and in line with previous studies, we find that the described pattern of accelerated population decline occurs for a wide range of parameter values if a concave allocation trade-off between independent growth and interaction investment is assumed. The undisturbed population typically disinvests first, which then forces the declining population to also disinvest, in favour of other energy sources. However, a decelerated population decline can occur if the adaptation of the undisturbed partner is relatively slow compared to environmental decay, reducing the speed of its disinvestment, or if the initial investment into the interaction was very high. Our results suggest that if actions are taken to save endangered populations, not only the evolution of the target species but also of their interaction partner, as well as the interaction between them should be considered.
... Dünyada tanımlanan böcek türünün sayısı yaklaşık 1 milyon olduğu ve yaklaşık 4.5-7 milyon türün de henüz keşfedilmediği tahmin edilmektedir(Stork, 2018).Böcekler ekosistemin işleyişinde canlıların yaşamı için çok önemli olan 3 doğal süreci gerçekleştirirler. Bunlar; çiçeklerin tozlaşması, bitkisel ve hayvansal organik maddelerin humusa dönüştürülmesi ve zararlı böceklerin üzerindeki doğal etkileridir(Fox, 2013). Yeşil gübre, uygulandığı toprağın fiziko-kimyasal ve biyolojik özelliklerini iyileştirmesi sonuçlarından biri de, böcekler için daha uygun yaşama alanı oluşturmalarıdır. ...
... Habitat degradation and loss are recognized among the primary causes for the widespread decline of many butterfly populations in Europe (Maes and Van Dyck 2001;van Swaay et al. 2010;Fox 2012). In this regard, the role of ecosystem engineers such as large ungulates can be locally predominant, as they can alter the availability of resources by modifying the physical state of biotic or abiotic materials (Jones et al. 1994) and, therefore, they can destroy, create and maintain habitats (Boogert et al. 2006;Byers et al. 2006;Streitberger and Fartmann 2013). ...
Wild boar is among the most abundant ungulates in Europe and its spread is locally creating concerns as a major threat to biodiversity. However, through their rooting activity, wild boars could play an effective role in the creation of specific microhabitat resources for plants and animals. Here, we tested the hypothesis that wild boar affects the habitat suitability to threatened butterflies, by evaluating the influence of rooting on multiple key aspects of the biology and ecology of the Mediterranean endemic Zerynthia cassandra. Namely, we used Z. cassandra as a model to test the effects of wild boar rooting on adult foraging opportunities, host plant occurrence, and oviposition site selection. We found that herbaceous communities disturbed by wild boar rooting have a higher proportion of plants representing nectar resources for early-flying butterflies. We also discovered that wild boar rooting positively influences the occurrence and abundance of the larval host plant of Z. cassandra, as well as the butterfly site selection for egg-laying. Our results indicate that wild boars may locally prove beneficial to endangered butterflies by favoring habitat quality and availability, and their role as ecosystem engineers should thus be further investigated to improve species and habitat management and conservation actions.
... Böcekler ekosistemin işleyişinde canlıların yaşamı için çok önemli olan 3 doğal süreci gerçekleştirirler. Bunlar; çiçeklerin tozlaşması, bitkisel ve hayvansal organik maddelerin humusa dönüştürülmesi ve zararlı böceklerin üzerindeki doğal etkileridir (Fox, 2013). Yeşil gübre, uygulandığı toprağın fiziko-kimyasal ve biyolojik özelliklerini iyileştirmesi sonuçlarından biri de, böcekler için daha uygun yaşama alanı oluşturmalarıdır. ...
YEŞİL GÜBRELEMENİN BÖCEKLER ÜZERİNE ETKİLERİ
... Most importantly, Lepidopterans are valuable indicators of environmental quality, considering their high degree of host-plant specialization and vulnerability to habitat deterioration [12]. Given their presence in a broad range of habitats, the loss of Lepidoptera may directly in uence the provisioning of key ecosystem services, such as pollination and natural pest control [13]. ...
Background
Recent studies indicated that frequent anthropogenic disturbances in tropical countries are primary drivers of the reduction in community diversity and local extinction of many insect taxa, including Lepidoptera. Biodiversity assessment provides information on the responses of different taxa to these anthropogenic changes, useful to develop evidence-based conservation strategies to reduce biodiversity loss. We assessed the impact of anthropogenic disturbances on lepidopteran assemblages across five different land uses (forest fragments, crop fields, Pasture land, rural settlement and undisturbed natural forest) in Choke Mountains, Ethiopia. Automatic light traps have been used in 16 sites, in 3 sites manual samplings have been performed. A total of 4,559 moths representing 14 families and 339 species were sampled. The highest diversity was obtained from the Natural Forest (269 species), followed by Forest Fragment (174), Pasture Land (148), Crop Fields (138), and Rural Settlement (136). The highest species-rich families were Geometridae (131 taxa), Erebidae (93 taxa), Tortricidae (40 taxa) and Sphingidae (17 taxa). Values calculated for the Shannon index were high, ranging between 4.78 for Natural Forests and 4.15 for Crop Fields. Simpson index indicated very high values of evenness, with all land use types above 0.97. The highest values of dominance were observed in Crop Field and Pasture Land, with the percentage of the dominant species around 10%. Estimated species richness by Chao-1 was highest within Natural Forest (366), followed by Pasture Land (256), Forest Fragment (241), Rural Settlement (233), and lowest in Crop Field (186), with the highest increase, if compared to the observed number of species, in Pasture Land (+ 73%) and Rural Settlement (+ 71%).
Conclusions
The results of this study will be useful for guiding conservation management priorities for preventing irreversible biodiversity losses and maintaining ecosystem services provisioning that are essential conditions for the sustainable development of rural communities.
... For some specialist ground beetles (Brooks et al., 2012), the loss of hedgerows and trees in the habitat likely triggered the decline in their numbers. Moreover, as the host plants of overwintering larvae reduces, the number of moths also decreases gradually (Fox, 2013;Mattila et al., 2006;Merckx et al., 2009;Pocock & Jennings, 2008). Therefore, the species with high habitat dependence will be more sensitive to the impact of human activities on their population dynamics. ...
Since the beginning of the Holocene era, human activities have seriously impacted animal habitats and vegetative environments. Species that are dependent on natural habitats or with narrow niches might be more severely affected by habitat changes. Malcus inconspicuus is distributed in subtropical China and highly dependent on the mountain environment. Our study investigated the role of the mountainous landscape in the historical evolution of M. inconspicuus and the impact of Holocene human activities on it. A phylogeographical approach was implemented with integrative datasets including double‐digest restriction site‐associated DNA (ddRAD), mitochondrial data, and distribution data. Three obvious clades and an east–west phylogeographical pattern were found in subtropical China. Mountainous landscape has “multifaceted” effects on the evolutionary history of M. inconspicuus, it has contributed to population differentiation, provided glacial refuges, and provided population expansion corridors during the postglacial period. The effective population size (Ne) of M. inconspicuus showed a sharp decline during the Holocene era, which revealed a significantly negative correlation with the development of cropland in a hilly area at the same time and space. It supported that the species which are highly dependent on natural habitats might undergo greater impact when the habitat was damaged by agricultural activities and we should pay more attention to them, especially in the land development of their distribution areas.
... While undertaking migratory flights, migrants often cross multiple regions, which makes them vulnerable to anthropogenic threats and complicates their conservation (Juhász et al., 2020;Malcolm, 2018;Martin et al., 2007;Reynolds et al., 2017;Runge et al., 2014), , Chowdhury, Braby, et al. (2021). Due to extensive anthropogenic pressure and human-induced climate change, insects, including butterflies, are declining worldwide (Chowdhury, 2023;Chowdhury, Jennions, et al., 2022;Fox, 2013;Habel et al., 2019;Hallmann et al., 2017;Wagner, 2020;Wagner et al., 2021;WallisDeVries et al., 2011;but see Sparks et al., 2005but see Sparks et al., , 2007. It is notable that more than half of migratory birds across all major flyways have declined in the last 30 years, suggesting that, in general, migratory species are at greater risk than sedentary species (Kirby et al., 2008). ...
Several hundred butterfly species show some form of migratory behaviour. Here we identify how the methodologies available for studying butterfly migration have changed over time, and document geographic and taxonomic foci in the study of butterfly migration. We review publications on butterfly migration published in six languages (English, Simplified Chinese, Traditional Chinese, Japanese, Korean, and Spanish), summarise how migration in butterflies has been studied, explore geographic and taxonomic patterns in the knowledge base, and outline key future research directions. Using English search keywords, we found only 58 studies from Asia; however, after searching in local languages, we found an additional 99 relevant studies. Overall, butterfly migration studies are mostly from North America and Europe. Most studies focus on three species: monarch (Danaus plexippus), painted lady (Vanessa cardui) and red admiral (Vanessa atalanta). About 62% of publications are focused on the monarch, with nearly 50% of migratory butterfly species mentioned in only a single paper. Several research methods have been applied to ascribe migratory status and to study the physiology, neurobiology, and ecology of migration; however, virtually all this research is on a handful of species. There remain hundreds of species for which we do not understand the comprehensive seasonal pattern of movement, flight destinations, wintering, or breeding grounds. A better understanding of movement ecology and migratory connectivity is needed to effectively conserve migratory butterflies. It is essential that research becomes more geographically and linguistically representative since migrants frequently cross political borders and international cooperation is necessary for their conservation. This article is protected by copyright. All rights reserved.
... Lepidoptera form a substantial component of invertebrate diversity, with over 2,900 species in the UK (Bradley, 2000), and are often used as indicators for terrestrial biodiversity (Merckx & Berwaerts, 2010). Significant declines have been documented for many Lepidoptera species with a range of possible drivers including agricultural intensification (Fox, 2013). The brown hairstreak butterfly is one example of a rapidly declining Lepidoptera species, and has been allocated priority status in the UK Biodiversity Action Plan (Merckx & Berwaerts, 2010). ...
Final report to Defra for project number BD2114.
Publicly available on Defra research reports website https://sciencesearch.defra.gov.uk/ProjectDetails?ProjectId=14826
... The adults usually are anthophilous; they visit flowers and suck nectar and/or pollen using a proboscis and are important nocturnal pollinators of many flowering plants (Krenn, 2010;Devoto et al., 2011;Kato and Kawakita, 2017;Ribas-Marquès et al., 2022). In addition, noctuid insects are important food sources for other aquatic and terrestrial organisms including fishes, frogs, spiders, birds, bats, predatory and parasitic insects (García-Navas and Sanz, 2011;Fox, 2013;Chapman et al., 2015). However, there is no accurate published information on the contribution of noctuid insects to ecological function and stability. ...
Although many noctuid insects are agricultural pests that threaten food production, they are also the major nocturnal pollinators of flowering plants. Larval foods of noctuid pest insects have been well studied for developing control strategies, but knowledge on host plants for the adults is rather scarce. Here, the impact of plant-derived foods on adult survival, fecundity and reproductive physiology of four global species of noctuid pests ( Mythimna separata Walker, Mythimna loreyi Duponchel, Athetis lepigone Möschler, and Hadula trifolii Hufnagel) was assessed in laboratory experiments. Our results indicated that nectar slowed testis decay and prolonged the oviposition period and lifespan, increasing fecundity. Acacia nectar increased the longevity of male and female adults by 3.2∼10.9 and 2.4∼5.0 days, respectively, and fecundity of females by 1.22∼3.34 times compared to water-fed individuals. The fitness among the different species of noctuid moths differed on specific pollen diets. On pine pollen, the fecundity of female moths of M. separata , A. lepigone and H. trifolii was 10.06, 33.52, and 28.61%, respectively, lower than those of the water-fed females, but the fecundity of female moths of M. loreyi on pine pollen was 2.11 times greater than for the water-fed individuals. This work provides valuable information on the nutritional ecology for noctuid moths, which can aid the development and design of nutritional attractants within noctuid pests-infected cropping systems and provide a basis for effective and targeted management of global noctuid pests.
... The present study on moth pollination is one of the few experiments conducted in natural conditions at landscape scale. Our findings demonstrate the ability of moths, especially of nursery pollinators, to disperse pollen over long distances in natural landscapes, revealing the efficiency of moths -which are declining in Europe (Fox, 2013;MacGregor et al., 2015)-for ensuring gene flow among plant populations. Therefore, our results emphasize the importance of nursery pollinator conservation for population sustainability of the host plant (Aslan et al., 2013). ...
High reciprocal pollination specialization leading to pollinator isolation can prevent interspecific pollen transfer and competition for pollinators. Sharing pollinators may induce mating costs, but it may also increase pollination services and pollen dispersal and offer more resources to pollinators, which may be important in case of habitat fragmentation leading to pollination disruption. We estimated pollen dispersal and pollinator isolation or sharing between two reproductively isolated genetic lineages of Silene nutans (Caryophyllaceae), which are rare and occur in parapatry in southern Belgium, forming two edaphic ecotypes. As inter-ecotypic crosses may lead to pollen wastage and inviable progeny, pollinator isolation might have evolved between ecotypes. Silene nutans is mainly pollinated by nocturnal moths, including nursery pollinators, which pollinate and lay their eggs in flowers, and whose caterpillars feed on flowers and seeds. Pollinator assemblages of the two ecotypes are largely unknown and inter-ecotypic pollen flows have never been investigated. Fluorescent powdered dyes were used as pollen analogues to quantify intra- and inter-ecotypic pollen transfers and seeds were germinated to detect chlorotic seedlings resulting from inter-ecotypic pollination. Nocturnal pollinators were observed using infrared cameras on the field, and seed-eating caterpillars were collected and reared to identify nursery pollinator species. No pollinator isolation was found: we detected long-distance (up to 5 km) inter-ecotypic dye transfers and chlorotic seedlings, indicating inter-ecotypic fertilization events. The rare moth Hadena albimacula, a nursery pollinator specialized on S. nutans, was found on both ecotypes, as well as adults visiting flowers (cameras recordings) as seed-eating caterpillars. However, S. nutans populations harbor different abundance and diversity of seed predator communities, including other rare nursery pollinators, suggesting a need for distinct conservation strategies. Our findings demonstrate the efficiency of moths, especially of nursery pollinators, to disperse pollen over long distances in natural landscapes, so to ensure gene flow and population sustainability of the host plant. Seed-predator specificities between the two reproductively isolated genetic lineages of S. nutans, and pollinator sharing instead of pollinator isolation when plants occur in parapatry, suggest that conservation of the host plant is also essential for sustaining (rare) pollinator and seed predator communities.
... Work in Canada suggests a positive relationship between whip-poor-will abundance and beetle abundance, but found that moths were less important (English et al. 2017). Moth populations have declined drastically in Europe (Fox 2013) and appear to be particularly sensitive to urbanization and agricultural intensification, in the form of increased pesticide application and the expansion of monoculture agriculture (Wagner et al. 2021). In the Midwest, agricultural intensification has contributed to declines in arthropods (Landis et al. 2008) and moth diversity (Harrison and Berenbaum 2013), possibly causing a reduction in food abundance for whip-poor-wills in a region where their declines appear to be severe. ...
Populations of avian aerial insectivores have declined across North America. A leading factor hypothesized to be driving these trends is a decline in prey populations, although a loss of suitable habitat on the landscape or other factors may also play a role. The Eastern Whip-poor-will (Antrostomus vociferus; hereafter: whip-poor-will) is an aerial insectivorous nightjar that has disappeared from many of its historic breeding locations. We investigated the role that food availability and land cover at multiple scales play in whip-poor-will distribution by estimating their abundance at 23 sites across central Illinois. To do this, we conducted nocturnal point counts to estimate whip-poor-will abundance and collected nocturnal insects using UV-light traps at these sites to quantify potential food abundance. Additionally, we described whip-poor-will diet using DNA metabarcoding of fecal samples. We found that the number of large moths at a site had a positive effect on the abundance of whip-poor-wills, aligning with our diet analysis which identified moths as the primary prey item for this species (present in 92% of samples). Whip-poor-wills also showed an affinity for forest edges, but only when edges were associated with high moth abundances. Conversely, developed land-cover in landscapes surrounding sites led to decreased whip-poor-will abundance. Given the continued expansion of developed areas, coupled with concerning trends in moth populations, declines in the abundance of this species may continue. Efforts should be made to protect and sustain moth populations and the impacts of development should be scrutinized in the pursuit of conserving whip-poor-wills.
... Since about two decades, the decline of biodiversity and insect populations in Europe has attracted considerable attention (e.g. Conrad et al., 2002Conrad et al., , 2006Fox, 2013;Fox et al., 2021;Groenendijk & van der Meulen, 2004;Habel et al., 2016Habel et al., , 2019Harvey et al., 2020;Maes & van Dyck, 2001;Mattila et al., 2008;Segerer & Rosenkranz, 2018;Swaay et al., 2006;Tarmann, 2019;Thomas et al., 2004;Wagner, 2020;Warren et al., 2001;Wepprich et al., 2019) and it was shown in the landmark study by Hallmann et al. (2017) that up to 75% of flying insect biomass was lost during the period 1989 to 2015 even in nature reserves at 60 localities in Western Germany. While most people agree that the use of pesticides (among which "neonicotinoides" received the greatest attention lately, see e.g., Blacquière et al., 2012;Woodcock et al., 2017;Warren et al., 2021), may account for some of this decline (especially as these chemicals can be distributed by wind from farmland into neighboring nature reserves), this is only a part of the truth. ...
The decline of biodiversity in general and of insect diversity in particular has been recognized as a major environmental problem in recent years. In this study, we analyze the distribution and the decline of populations of forester moths of the genus Jordanita in Central Europe since 1950 as a type example of the loss of grassland biodiversity, and discuss potential drivers causing this decline. Based on the extensive work in museums and private collections, a literature review and own observations, and including data as far back as 1834, this genus helps to understand the deeper reasons of insect population and biodiversity decline, as the well investigated six Central European species cover a broad range of extensive grassland habitats (fens to low‐production grassland and xerothermic steppes) from low altitudes to high alpine meadows. Therefore, they monitor processes relevant also to other, less investigated grassland species. Although there are differences in research intensity over time and in different natural areas, we show that in the whole of Central Europe, the populations of all six investigated Jordanita species broke down massively in the past decades, both in terms of number of populated habitats (about 400 recorded localities after the year 2000 compared with a total number of about 1600 at all times, cumulated for all six species) and in terms of number of individuals. On the other hand, some natural areas on a regional scale have more or less maintained their Jordanita populations, due to conservative land use and due to the early implementation of conservation and protection management plans. The reasons of decline are manifold and monitored in detail by the different species with their different habitat requirements. They comprise (1) loss of habitats due to land use changes (both intensification and abandonment), (2) loss of habitats due to urbanization and construction work, (3) loss of habitat networks to cope with small‐scale extinction events, (4) more intensive growth of grass at the expense of other plants in otherwise undisturbed habitats due to fertilization through the air (increased nitrogen levels due to human activities) and (5) use of pesticides. Jordanita species (Lepidoptera) as a proxy for grassland species in general show a strong decline in Central Europe since 1950 which is mainly related to changing agricultural landuse and destruction of habitats. This article reviews thousands of observations, shows the decline and discusses the reasons in detail.
... The complex outcomes of trait-based studies of European moths are perhaps unsurprising given the range of interacting anthropogenic factors suspected to influence population size, principally land-use change and climate change, with pollution and non-native species thought to play smaller roles (Wagner et al. 2021). Multiple drivers act as stressors, both directly and indirectly, with resultant demographic changes dependent on unique physiological, biogeographical and ecological requirements of each taxon (Fox 2013), and overall the mechanisms underlying population declines remain poorly understood (Wagner et al. 2021). Understanding the relative importance of the drivers of decline will help prioritise policy responses. ...
Trait-based approaches are advocated for their ability to predict population declines in data-deficient taxa and regions, potentially benefiting biodiversity conservation. Several reviews have, however, highlighted inconsistent results between traits studies, sometimes even for the same taxonomic group and biogeographical region. Traits studies of moths are commonplace and support this pattern of inconsistency, albeit with largely congruous results for traits relating to dietary and habitat breadth. We use the most comprehensive moth trends available, those for British macro-moths, to test the utility of traits approaches using a multi-model inference approach whilst controlling for phylogeny. We expected our results to add to the general pattern of inconsistency among moth traits studies. We found strong associations for several traits; woodland moths and those feeding on grasses and lichens or algae tend to be faring well, whereas declines were associated with univoltinism, narrow diet breadth, nocturnal flight period, overwintering as an egg, moorland habitat preference, and feeding on forbs. Abundance and distribution trends produced different outcomes, with no trait having significant associations for both measures of change. Our findings corroborate previous studies for certain traits, but for others they provide further evidence that traits analyses can yield inconclusive or contradictory results. We suggest that these inconsistencies are rooted in the complex drivers of population change, as well as incomplete knowledge of some traits. Overall, our study adds to evidence that unequivocal relationships between traits and population changes are lacking for most parameters, limiting the usefulness of trait-based approaches in predicting species declines.
... Hallmann et al. 2017;Seibold et al. 2019). But already before that studies showed concerning declines of different insect groups (Biesmeijer et al. 2006;Brooks et al. 2012;Conrad et al. 2006;Fox 2013;Thomas et al. 2004). Declines may neither apply to all insect groups nor be apparent at all places and times (Hallmann et al. 2020;Macgregor et al. 2021;Schuch et al. 2012b;van Klink et al. 2020), but in the last years evidence has grown that in many regions of the world there are ongoing severe changes in insect populations though missing long-term data complicates gain of knowledge. ...
Pollinating insects like bees and hoverflies play an important role in natural ecosystems and in agriculture. They pollinate the majority of wild plant and crop species worldwide while visiting flowers for their own food supply. Like many other insect groups wild (= unmanaged) pollinators are in decline. A lot of evidence for this decline comes from Europe, where intensified agriculture was identified as the main driver. One of the major issues is the lack of floral resources due to a loss in flower-rich habitats. Measures for enhancing pollinators therefore typically aim for increasing the availability of floral resources in agricultural landscapes. This can for example be achieved by means of flower strips, which are prominently promoted in form of EU agri-environmental schemes. But also semi-natural habitats like hedges or herbaceous structures along slopes or ditches can be valuable flower providers and can be established as enhancement measures in agro-ecosystems. However, flower strips, hedges and herbaceous semi-natural habitats may vary in their effect on wild pollinators due to differences in floral resources and other habitat characteristics, e.g. the provision of nesting sites or a beneficial microclimate. Furthermore, their impact may depend on the dominant agricultural land use in their surroundings and the resources that are available there. Intensive apple orchards for example seem to be of limited value for wild pollinators because apart from the apple bloom they provide only few floral resources. In combination with the fact that apples require insect pollination this makes intensive apple orchards relevant research objects for finding suitable pollinator enhancement measures. In this theses, I aimed at understanding how wild pollinators react on different enhancement measures in intensive apple orchards and whether the measures complement each other in a beneficial way. The overall goal was to find out how wild pollinators can efficiently be enhanced in landscapes with high proportions of intensive apple orchards. The main focus is on pollinator conservation, but I also address the question whether enhancement measures help increasing apple pollination.
In Chapter I I compare the effectiveness of perennial flower strips, hedges and improved hedges (complemented with a sown herb layer). I found that wild bee abundance and species richness were highest in flower strips followed by improved hedges. Also hoverflies were most abundant in flower strips, but not more species rich than at control sites. Flower abundance was the main driver for wild bee diversity, whereas hoverflies were largely unaffected by floral resources. Only the wild bee but not the hoverfly community composition differed between the control orchard edge and the enhancement measures. The enhancement measures had neither an effect on the pollinator diversity within the orchards nor on apple flower visitation. I conclude that perennial flower strips are the most effective measure to enhance wild pollinators in intensive apple orchards though hedges should not be ignored as they attracted a different bee community than the flower strips. However, the increased diversity of wild pollinators did not translate in increased apple-flower visits, thus had no effect on pollination.
Chapter II sheds light on the temporal interplay of the enhancement measures. Diverse wild bee communities require a continuous flower supply over the entire vegetation season that sustains long-lived social species as well as solitary species, which are active only temporarily. I hypothesised that hedges and flower strips complement each other in providing flowers at different periods of the year and that the improved hedges combined both flowering periods. Indeed, hedges and flower strips complemented each other. The hedges flowered from spring to early summer and attracted most wild bees in this period. In early summer the flower strips started to provide a continuous high floral supply until late summer. In contrast to the flower strips, the hedges showed fluctuating floral resources. This difference in the continuity of flower provision was a main reason for the generally higher wild bee diversity in flower strips as found in Chapter I. The improved hedges, which would have in theory been superior to both hedges and flower strips, performed less well than expected mostly due to varying establishment success of the sown herb layers. The flower strips started flowering much earlier in the second year after establishment and showed a different flower composition, which both translated in differences in the wild bee community across the years. In the third year wild bee diversity however decreased in comparison to the first two years in the flower strips. I conclude that woody vegetation and flower strips should be managed together to enhance bee pollinator communities in agricultural landscapes. To stabilise the fluctuating short-term flower supply in hedges the diversity of bee-attractive shrubs with complementary phenology should be promoted. The establishment of herb layers along hedges may be useful, but only if enough space and light is available. Flower strips should be perennial because they attract different bee communities at different ages and start flowering much earlier from the second year on. Maintenance measures should ensure long term flower richness in the flower strips.
Chapter III focuses on other semi-natural habitat types than hedges, namely small-scale patches with spontaneous herbaceous vegetation. I compared explicitly flower-rich semi-natural habitat patches along slopes, overgrown fences or ditches with the flower strips. As before, the flower strips were superior in attracting a high pollinator diversity due to a higher floral richness, whereas in the semi-natural habitat patches the pollinator diversity varied strongly due to differences in the flower supply. However, the bee species composition differed between the flower strips and the semi-natural habitat patches. The patches attracted bee species with different pollen specialization than the flower strips. I conclude that herbaceous semi-natural habitat patches are not as attractive for pollinators as flower strips, but nevertheless play an important role for pollinator diversity by providing different flower species at different times. Semi-natural habitat patches typically do not compete with agricultural land use, can often be improved or enlarged at low costs and thus have a high potential to promote pollinator conservation in intensive agricultural landscapes.
Chapter IV investigates the plant-pollinator-networks in the orchards and whether these are affected by the presence of hedges or flower strips. Of special interest in this context are those pollinator species that visit and potentially pollinate apple flowers. Therefore, only apple-pollinators were considered in the network analysis. The networks were regarded from two perspectives: from the orchard plant perspective and from the pollinator perspective. For this, two indices were calculated: plant generality, which indicates the number of visiting pollinator species per plant species, and apple-pollinator generality, i.e. the number of plant species visited per pollinator species. Plant generality in orchards was not influenced by the presence of enhancement measures. So plants within the orchards were not visited by a higher diversity of species when flower strips or hedges were present. This applied also to the apple flowers. In contrast, apple-pollinator generality was higher in the orchards with enhancement measures, which indicates a larger food supply for apple pollinators before and after the apple flower. This was especially true for flower strips. Thus, planting hedges and flower strips does not increase the diversity of wild pollinators visiting apple flowers, but particularly flower strips are beneficial for apple pollinators after the mass-flowering event and help stabilizing apple pollinator populations.
In summary, the enhancement measures have the potential to increase pollinator diversity in intensive apple orchards, but the enhancement measures differ in their effect on wild pollinators. The perennial flower strips turned out highly efficient in enhancing wild bees, but the hedges and semi-natural habitat patches also played a non-neglectible role. Their habitat quality could be increased by improvements and maintenance measures. Hoverflies in contrast to wild bees could only be enhanced in terms of abundance, but not in species richness, which either calls for further research on how to enhance this species group in intensive agrarian landscapes or suggests the conclusion that hoverflies are not a meaningful target species group in the studied landscape. Though the enhancement measures were relatively successful in terms of pollinator conservation, they did not increase the visitation rate of apple flowers. Yet, they may indirectly stabilize the apple-pollinator populations by providing them with floral resources before and after the apple bloom.
... Habitat degradation and loss are recognized among the primary causes for the widespread decline of many butterfly populations in Europe (Maes and Van Dyck 2001;van Swaay et al. 2010;Fox 2012). In this regard, the role of ecosystem engineers such as large ungulates can be locally predominant, as they can alter the availability of resources by modifying the physical state of biotic or abiotic materials (Jones et al. 1994) and, therefore, they can destroy, create and maintain habitats (Boogert et al. 2006;Byers et al. 2006;Streitberger and Fartmann 2013). ...
Wild boar is among the most abundant ungulates in Europe and its spread is locally creating concerns as a major threat to biodiversity conservation. However, through their rooting activity, wild boars could play an effective role in the creation of specific microhabitat resources for plants and animals. Here, we tested the hypothesis that wild boar affects the habitat suitability to threatened butterflies, by evaluating the influence of rooting on multiple key aspects of the biology and ecology of the Mediterranean endemic Zerynthia cassandra . Namely, we used Z. cassandra as a model to test the effects of wild boar rooting on adult foraging opportunities, host plant occurrence, and oviposition site selection. We found that herbaceous communities disturbed by wild boar rooting have a higher proportion of plants representing nectar resources for early-flying butterflies. We also discovered that wild boar rooting positively influences the occurrence and abundance of the larval host plant of Z. cassandra , as well as the butterfly site selection for egg-laying. Our results indicate that wild boars may locally prove beneficial to endangered butterflies by favoring habitat quality and availability, and their role as ecosystem engineers should thus be further investigated to improve species and habitat management and conservation actions.
... Numerous studies have concluded that invertebrates are declining, in both biomass (Hallmann et al. 2017) and relative frequency (Biesmeijer et al. 2006;Fox 2012;van Strien et al. 2013;Fox et al. 2014;Powney et al. 2019). The precise reasons for these declines have never been determined, although many possibilities have been suggested, including: agricultural intensification (IPBES 2018; Sánchez-Bayoa and Wyckhuys 2019) and use of pesticides and herbicides (Reynolds 2019); urbanisation (Corcos et al. 2019;Jones and Leather 2012); roadkill (Baxter-Gilbert et al. 2015); effects of atmospheric nitrification on vegetation structure (Phoenix et al. 2012, Wallisdevries andVan Swaay 2006); physiological effects of climate change on flowering plants (Scaven and Rafferty 2013) and climate change (e.g. ...
We describe significant range changes in Leucozona glaucia (Linnaeus, 1758) during the period 1980 to 2021, using two different techniques. Relative frequency of the species corrected for recording effort was estimated using FRESCALO and species distribution models were fitted using Maxent. The distributions estimated for two spans of years at the beginning and end of this period were compared. Both methods suggest that the range of L. glaucia has changed substantially. It has contracted in southeast and eastern England but has expanded in northwest Scotland and perhaps also more generally in western Britain. The reasons for these changes are as yet unconfirmed, but we suspect that the principal driver is increasingly frequent periods of water and heat stress. We hypothesise that these stresses affect the larval stages.
... Insects form the biological foundation for all terrestrial ecosystems. Despite their critical importance for the ultimate functioning and sustainability of ecosystems worldwide, for many years, insects have been systematically underrepresented in biodiversity and conservation studies [18][19][20] . Drivers of population decline in the above orders are discussed below. ...
Insects are an important component of the ecosystem and fast dwindling of its diversity is reported globally. The International Union for Conservation of Nature has assessed a total of 77,435 species of insects between 1996 and 2020, of which 18,180 (23.47%) species are reported to be threatened and the majority of threatened species was reported in Odonata followed by Orthoptera, Coleoptera, Lepidoptera and Hymenoptera. Out of 1843 species listed as critically endangered, endangered, extinct, extinct in wild and vulnerable, from the literature it was found that 596 are predators, 40 are
pollinators, 164 are saprophagous, 620 are herbivores, 272 are omnivores, 137 are parasites and 14 are unknown. This study provides concise information on insect diversity, global threat status and major drivingfactors for population decline, which will be helpful in determining the priority insect groups that require conservation.
... For instance, the subtribes Phaegopterina, Ctenuchina, and Euchromiina represent highly diverse groups in Mexico, and are consistent with previous surveys in other Neotropical regions (Hilt and Fiedler 2005, Muñoz and Amarillo-Suárez 2010, Beccacece et al. 2016b) and in Mexico Beutelspacher 2000, Turrent-Díaz andPescador Rubio 2013). Historical surveys of the tribe Arctiini in Mexico also revealed an apparent decrease in the number of species recorded (N = 254, see Supp Material 3 [online only]) over the last decade, and perhaps indicative of potential population decline or local extinctions, likely due to habitat loss and fragmentation stressors (Goulson et al. 2008, Fox 2013, Nunes et al. 2016, Hallmann et al. 2017, Wepprich et al. 2019). ...
The Mexican lepidopteran fauna is particularly diverse, but many moth groups remain poorly documented. The tribe Arctiini is a species-rich group that has been used as a reliable indicator of environmental change. However, little is known about the fauna of the tribe Arctiini in Mexico, and there is no exhaustive review of its diversity and distribution patterns. Our aims were: 1) to account for the species diversity and distribution patterns of the tribe Arctiini; 2) to build spatial distributions and discuss possible changes in the distribution areas of the tribe Arctiini using conservative (RCP 2.6) and liberal (RCP 8.5) future climate scenarios; and 3) to discuss the conservation implications for key taxa that due to their life history characteristics and restricted distribution, might require particular conservation actions. We compiled a total of 16,385 records and 548 species in seven subtribes. Diversity profiles revealed higher cumulative species richness and diversity for the subtribes Phaegopterina, Ctenuchina, and Euchromiina, and we identified a pattern of decreasing species diversity with elevation. In addition, we estimated that 35% and 84% of modeled species in future conservative and liberal climatic scenarios, respectively, would result in significant losses of climatic suitability and shifts in spatial distribution. The endemic species, Virbia semirosea, Poliopastea jalapensis, and Pygoctenucha azteca would likely reduce their distribution by approximately 50% in both climatic scenarios. Maintaining a network of highly threatened habitats (e.g., cloud forests, tropical rain forests) will be essential to preserve persisting species populations and to increase likely (re)colonization events.
... Due to the elevated degree of host-plant specialization of many butterfly and moth species and their high vulnerability to habitat deterioration, the presence of Lepidoptera often represents a critical indicator of environmental quality (Erhardt and Thomas, 1991). Unfortunately, massive decline of some species and dramatic changes in butterfly and moth biodiversity from different geographic areas have been reported in the last decades (Sánchez-Bayo and Wyckhuys, 2019) and the steepest declines occurr in those environments with a massive use of insecticides (Fox, 2013;Gilburn et al., 2015). Lepidoptera are particularly susceptible to both synthetic insecticides and biopesticides, which are often specifically designed to target them since many species represent destructive pests of commercially important crops (Sree and Varma, 2015). ...
As synthetic pesticides play a major role in pollinator decline worldwide, biopesticides have been gaining increased attention to develop more sustainable methods for pest management in agriculture. These biocontrol agents are usually considered as safe for non-target species, such as pollinators. Unfortunately, when it comes to non-target insects, only the acute or chronic effects on survival following exposure to biopesticides are tested. Although international boards have highlighted the need to include also behavioral and morphophysiological traits when assessing risks of plant protection products on pollinators, no substantial concerns have been raised about the risks associated with sublethal exposure to these substances. Here, we provide a comprehensive review of the studies investigating the potential adverse effects of biopesticides on different taxa of pollinators (bees, butterflies, moths, beetles, flies, and wasps). We highlight the fragmentary knowledge on this topic and the lack of a systematic investigation of these negative effects of biopesticides on insect pollinators. However, we have found that all the major classes of biopesticides, besides their direct toxicity, can also cause a plethora of more subtle detrimental effects in both solitary and social species of pollinators. Although research in this field is growing, the current risk assesment approach does not suffice to properly assess all the potential side-effects that these agents of control could have on pollinating insects. Given the urgent need for a sustainable agriculture and wildlife protection, it appears compelling that these so far neglected detrimental effects should be thoroughly assessed before allegedly safe biopesticides can be used in the field and, in this view, we provide a perspective for future directions.
... At multiple levels of biological organization, from genes to populations to ecosystems, biodiversity is being lost at a rate that is transforming every region of the planet (Barnosky et al., 2012). Insect declines have been reported in nearly all habitats from the Arctic (Gillespie et al., 2020;Høye et al., 2013;Loboda et al., 2018) to the tropics (Roubik, 2001;Salcido et al., 2021); in developed areas (Theng et al., 2020), wildlands , and nature reserves (Hallmann et al., 2017;Rada et al., 2019); and across taxa from hoverflies (Hallmann et al., 2021) to dragonflies (Nakanishi et al., 2018) to butterflies and moths (Conrad et al., 2006;Fox, 2013;Thomas et al., 2004;Wagner, Fox, et al., 2021;Warren et al., 2021). Propelling these declines are a multitude of threats including habitat destruction, agricultural intensification, climate change, invasive species, and more (see Cardoso et al., 2020;Harvey et al., 2020;Wagner, 2020;Wagner, Grames, et al., 2021). ...
Biodiversity is in crisis, and insects are no exception. To understand insect population and community trends globally, it is necessary to identify and synthesize diverse datasets representing different taxa, regions, and habitats. The relevant literature is, however, vast and challenging to aggregate. The Entomological Global Evidence Map (EntoGEM) project is a systematic effort to search for and catalogue studies with long‐term data that can be used to understand changes in insect abundance and diversity. Here, we present the overall EntoGEM framework and results of the first completed subproject of the systematic map, which compiled sources of information about changes in dragonfly and damselfly (Odonata) occurrence, abundance, biomass, distribution, and diversity. We identified 45 multi‐year odonate datasets, including 10 studies with data that span more than 10 years. If data from each study could be gathered or extracted, these studies could contribute to analyses of long‐term population trends of this important group of indicator insects. The methods developed to support the EntoGEM project, and its framework for synthesizing a vast literature, have the potential to be applied not only to other broad topics in ecology and conservation, but also to other areas of research where data are widely distributed. A systematic approach to reviewing the literature can reduce bias in the types of datasets identified to understand conservation issues. Here, we present a community‐driven evidence synthesis framework that can be adapted to gather and assess evidence from many broad topics in conservation and apply the approach to gather datasets documenting long‐term changes in insect populations.
... Moth abundance has decreased significantly in recent decades, and their occurrence is likely to be affected by many environmental factors including light pollution and changes in land-use and climate (Fox et al., 2011(Fox et al., , 2014Macgregor et al., 2015;Péter et al., 2020). The larvae of most lepidopteran insects are agricultural and forestry pests, while the adults (moths or butterflies) are usually pollinators of many plant species and a food source for many organisms (such as birds, bats, fishes, frogs, and spiders) (Devoto et al., 2011;Fox, 2013;Kato & Kawakita, 2017;Liu, Fu, et al., 2017). Therefore, a decrease in moth abundance will also affect the abundance of other organisms in the ecosystem. ...
Nocturnal moths are important pollinators of plants. The clover cutworm, Hadula tri-
folii, is a long- distance migratory nocturnal moth. Although the larvae of H. trifolii are
polyphagous pests of many cultivated crops in Asia and Europe, the plant species
pollinated by the adult are unclear. Pollen species that were attached to individual
migrating moths of H. trifolii were identified based on pollen morphology and DNA to
determine their host plants, geographic origin, and pollination areas. The moths were
collected on their seasonal migration pathway at a small island, namely Beihuang, in
the center of the Bohai Sea of China during 2014 to 2018. Pollen was detected on
28.60% of the female moths and 29.02% of the male, mainly on the proboscis, rarely
on compound eyes and antennae. At least 92 species of pollen from 42 plant fami-
lies, mainly from Asteraceae, Amaranthaceae, and Pinaceae, distributed throughout
China were found on the test moths. Migratory H. trifolii moths visited herbaceous
plants more than woody plants. Pollen of Macadamina integrifolia or M. tetraphylla
was found on moths early in the migratory season. These two species are distrib-
uted in Guangdong, Yunnan, and Taiwan provinces in China, indicating that migratory
moths probably traveled about 2000 km from southern China to the Beihuang Island
in northern China. Here, by identifying plant species using pollen, we gained a better
understanding of the interactions between H. trifolii moths and a wide range of host
plants in China. This work provides valuable and unique information on the geographi-
cal origin and pollination regions for H. trifolii moths.
... Further, there is evidence to suggest that ALAN can negatively affect moth reproduction, development of larvae, and diapause in pupae [31]. European moth abundance has been declining over the last few decades (decline recorded from 1982-2017 in Britain) [175] and increased light pollution due to urbanisation may be playing a role in this population fall [96,188,202]. Future research should investigate the impact of light pollution on insect populations relative to other environmental stressors, such as climate change, insecticides, and invasive species. ...
Humans first began using artificial light at night (ALAN) during the industrial revolution and sources of light have diversified and intensified considerably over the last century. Light pollution has previously been defined under two separate branches, “ecological light pollution” where the natural light patterns are altered in marine and terrestrial environments, and “astronomical light pollution” where the view of the night sky is reduced. Natural light is vital for the regulation of animal behaviour and interactions. Surprisingly, this environmental stressor did not become a worldwide concern until 2009. Since then, research into this subject has substantially increased, with studies highlighting the detrimental effects of ALAN. These effects can be serious for many organisms and include the disruption of the essential circadian rhythms that most organisms use to time important behaviours such as foraging, reproduction, and sleep. Whether all organisms possess phenotypic plasticity to effectively adapt to increasing and changing artificial light pollution is not yet known. Here, we summarise the effects of light pollution among many different species, from marine to terrestrial, with a focus on the areas that require further research to enhance our knowledge of this subject. The aim of this review is to raise awareness and enhance understanding about this little-discussed environmental concern, including some novel ideas on camouflage and polarised light pollution, hopefully encouraging future research into the effects of light pollution on organism behaviour.
... Biella et al., , 2020Brosi et al., 2017;Ferrero et al., 2013;Lopezaraiza-Mikel et al., 2007). Well documented examples come from moths and ground beetles that are declining due to the loss of specific host plants that they need as food or as overwintering shelters (Brooks et al., 2012;Fox, 2013;Mattila et al., 2006). ...
Les relations entre plantes et insectes herbivores jouent un rôle clé dans la structuration des écosystèmes terrestres et régissent la dynamique des populations qui les composent. Ces relations sont souvent des interactions complexes, impliquant aussi bien des effets directs qu‘indirects. Comprendre ces interactions demeure une nécessité et ce non seulement dans un objectif de mettre en place des programmes de lutte biologique, mais également afin de comprendre les dynamiques des communautés dans les écosystèmes naturels. Notre travail de recherche s‘insère à l‘interface entre écologie des communautés et recherche agronomique. Son objectif principal est de comprendre l‘effet des interactions trophiques complexes sur la structure et la stabilité des communautés d‘herbivores et de déterminer les relations entre diversité des ennemis naturels et suppression des herbivores. Les expériences ont été conçues pour tester les prévisions théoriques et les mécanismes expliquant les conséquences de ces interactions au sein des communautés. Le travail mené au cours de cette thèse comporte trois chapitres. Dans le premier chapitre, nous avons déterminé l‘impact de l‘élimination d‘une plante généraliste, Solanum mauritianum, sur la structure de la communauté de thrips chez Lantana camara et Ipomoea indica. L‘élimination de la plante généraliste a provoqué une augmentation de l‘abondance de l‘espèce Franklieniella occidentalis chez I. indica. En revanche, chez L. camara, nous avons observé une diminution d‘abondance de cette même espèce de thrips. Le traitement a également provoqué une augmentation d‘abondance de l‘espèce Hercinothrips patersonii chez L. camara. Malgré ces changements d‘abondance de certaines espèces, l‘élimination des fleurs de S. mauritianum n‘a pas montré d‘effet significatif sur l‘abondance totale ainsi que la richesse spécifique de la communauté de thrips. Dans le second chapitre, nous avons déterminé les effets indirects d‘un ennemi naturel sur la coexistence des herbivores, leur développement sur une plante de qualité sub-optimale et enfin sur leurs changements de traits d‘histoire de vie. Quatre communautés ont été mises en cage insect-proof et leur dynamique a été suivie sur plusieurs générations. Le modèle d‘étude est constitué de trois espèces d‘herbivores en compétition. Deux compétiteurs supérieurs, l‘acarien Tetranychus urticae et le puceron Myzus persicae, ainsi qu‘un compétiteur inférieur, le thrips Echinothrips americanus. Nous avons également intégré deux espèces d‘ennemis naturels spécialistes des deux compétiteurs supérieurs : l‘acarien Phytoseiulus persimilis (prédateur de T. urticae) et l‘Aphidiinae Aphidius colemani (parasitoïde de M. persicae). Dans le cadre de notre expérimentation, nous avons utilisé deux espèces de plantes hôtes : le haricot (Phaseolus sp.) et le tabac (Nicotiana tabacum). Les résultats ont montré que les deux espèces d‘ennemis naturels avaient un effet indirect positif sur la population du compétiteur inférieur E. americanus, favorisant ainsi sa survie, grâce à l‘élimination des compétiteurs supérieurs M. persicae et T. urticae. De plus, nos résultats ont également montré que le parasitoïde A. colemani, en limitant les populations de M. persicae sur le tabac, était susceptible de provoquer un changement de plante hôte d‘E. americanus vers le tabac, qui est pour lui une plante de qualité sub-optimale, avec des conséquences sur ses traits d‘histoire de vie. Dans le troisième chapitre, nous avons évalué l‘effet de la diversité des ennemis naturels sur la suppression des herbivores et la stabilité des communautés. Nous avons organisé un système constitué de quatre espèces d‘herbivores, Tetranychus urticae, Myzus persicae, Echinothrips americanus et Frankliniella occidentalis, et quatre espèces d‘ennemis naturels, Cheilomenes sulphurea, Aphidius colemani, Amblyseius swirskii et Nesidiocoris volucer. Nous avons établi huit communautés où les espèces d‘herbivores étaient invariables...
... Butterflies and moths have high level of host plant specialization and are therefore vulnerable to habitat deterioration [31]. They also have a wide range of distribution and important for the delivery of key ecosystem services such as biological pest control and pollination [32]. Moths, which are about 10 times more different than butterflies, constitute important prey items for bats and sustain population levels of a myriad of other insectivorous animals [33]. ...
The world's population exceeded 7 billion in late 2011 and it is expected to reach 9.3 billion by 2050. Meanwhile, demand for food is predicted to increase between 50 and 100% by 2050. To meet the food demands of the increasing population, agricultural intensification practices including growing monocultures of high-yielding crop varieties and increased applications of fertilizers and pesticides have been used to increase productivity. These practices, however, impact negatively on biodiversity of existing flora and fauna, particularly causing huge declines in insect biodiversity. This chapter reviews present state of knowledge about agricultural intensification practices and global decline of insect biodiversity (i.e., pest and beneficial insect species) in intensive agricultural system and point out the likely drivers of these declines. It concludes the review by examining sustainable agricultural intensification practices that could be used to mitigate these biodiversity declines while maintaining productivity in intensive agricultural systems.
... The shift from original natural habitats to urban habitats triggers profound changes in many environmental factors (McDonnell and Hahs, 2008;Seress et al., 2014). The alteration of vegetation cover; an increase of chemical, light, and noise pollution; and higher environmental temperatures have been reported as the main effects of urbanization (Yow, 2007;Fox, 2013;Díaz et al., 2022). Those changes have strong cascading effects on species composition of plant and animal communities at both regional and global scales (Grimm et al., 2008;Arroyo-Rodríguez et al., 2013;Aronson et al., 2014) and usually involve a dramatic reduction of biodiversity (McDonnell and Hahs, 2008;Seress et al., 2014;Beninde et al., 2015;Sherry, 2021). ...
Urbanization constitutes one of the most aggressive drivers of habitat and biodiversity loss worldwide. However, studies focused on determining the response of local biodiversity to urbanization are still scarce, especially in tropical ecosystems. Urban ecosystems are characterized by low biological productivity which in turn leads to a reduction in biodiversity. However, the responses to urbanization should be species dependent. For instance, changes in the availability of resources can favor certain species with specific characteristics. We assessed the effects of the urbanization process on a bird community in a city located in the Tropical Andes of southern Ecuador, a region widely recognized for its diversity and endemism of birds. We selected three independent localities in each of the four levels of the urbanization gradient in the study area (forest, forest-pasture, pasture, and urban). In each locality, we sampled the bird community by visual and auditory surveys along 1 km transects between 2016 and 2017. We recorded a total of 1,257 individuals belonging to 74 bird species. We evaluated if the responses of richness and abundance of birds are dependent on trophic guild and foraging strata. We found a significant decrease in bird species richness and abundance from forest to urban sites. However, the response of birds was dependent on the trophic guild and foraging strata. Granivorous birds showed a positive response associated with the urbanization gradient while insectivorous birds showed a negative response. Insectivorous birds were more abundant in forest sites and decreased in abundance across the urbanization gradient. We found that the proportion of birds using different foraging strata drastically changed along urban gradient. Forest sites exhibited a bird community using a variety of habitats, but the bird community became simpler toward the most urbanized sites. Our findings showed different effects of urbanization on bird communities. The ugly: urbanization leads to a dramatic reduction in the diversity of birds, which is consistent in cities with different characteristics and ecological contexts. On the other hand, the responses of bird guilds to urbanization are species dependent. Some guilds are positively impacted by urbanization and show increases in species richness and abundance while other guilds are negatively impacted.
... Cataclysms insect extinctions and rapid declines in insect populations have been documented recently in other parts of the world (e.g. Conrad et al., 2006;Goulsen et al., 2008;Nilsson et al., 2008;Potts et al., 2010;Ilyinykh, 2011;Fox, 2013;Fox et al., 2014;Hallmann et al, 2017;Milman, 2022). Despite these studies, the true rate of insect and other animal biodiversity decline is likely to be severely underestimated (Régnier et al., 2015;Geyle et al., 2021). ...
Abstract: Field evidence by the first author during 1062- 2022 has revealed that the Botany Bay Cockroach, Polyzosteria limbata Burmeister 1838 (Dictyoptera: Blattidae: Polyzosteriinae) is apparently extinct in the woodlands and forests of the Blue Mountains, New South Wales, Australia. The cockroach was relatively common and widespread throughout the mountains during 1062-1965 and during 1975-1977 but possibly during the 1980s an d 190s it became extinct or at least extremely rare. During the 1960s and from 1977-79 I undertook most field studies in the lower Blue Mountains around Glenbrook, Lapstone, Blaxland, Warrimoo and Springwood. From 1997 onwards Ive explored the woodlands a d forests of these towns as well as extensive field work in the Blue Mountains National Park west of Glen broom as well as Katoomba, Leura, Woodford, Mount Victoria, Blackheath etc. During 1997-2022 I have failed to find a single specimen of this cockroach anywhere in the Blue Mountains,. Previously very little has been published on the biology and distribution of this distinctive insect. The reasons for the demise of this ground dwelling cockroach is probably due to an increased incidence of fires in the Blue Mountains from the 1980s onwards. It would appear that predators or climate change may not have been significant in this species demise.
... Undoubtedly, factors that are responsible for the Insectaggedon also affect other organisms and cause a general decline in the biodiversity of plants, insects, amphibians, birds, mammals, and other species that have been present in our landscapes (Losey and Vaughan 2006;Fox 2013;Benton et al. 2002;Thomas et al. 2004;Hallmann et al. 2014;Ptaszyńska et al. 2021;Tauber et al. 2021). Considering that some species have lost over 80% of their habitats over the last 100 years, some scientists estimate that 50% of local populations might have already gone extinct (Ceballos et al. 2015;Ceballos et al. 2017;Ceballos and Ehrlich 2018). ...
Living in an epoch of forcible human-instigated transformations, we can witness their effects both on the Earth's geology and its ecosystems. So significant are these changes that we are often said to be witnessing the birth of a new epoch-the Anthropocene. This era is believed to be driven by the "Great Acceleration" that sees human population grow rapidly, which results in a drastic increase in the demand for energy, land, and water. The expanding human population enters areas previously inhabited by other organisms and displaces them from their natural habitats. This has already led to the sixth mass extinction, Insectageddon and an explosive spread of pathogens attacking native populations of plants, animals, and humans. Ongoing coronavirus pandemic and other diseases triggered by viruses, bacteria, and fungi are linked to the worldwide destruction of ecosystems. Humans' autodestructive behaviour also poses a threat to other species and wildlife in general.
... These changes result in the destruction of food sources, nesting, oviposition, resting, and mating sites [95]. The increase in population pressure and urbanization of wild and agricultural lands has disrupted the habitat of wild pollinators viz., moths [118], butterflies [119], and bees [70,71,120,121] and managed pollinators experienced sudden colony losses [122]. With the increased demand for food crops and higher productivity by use of either plant production or plant protection chemicals has killed the pollinators directly, and eradicated alternative pollen sources from their natural forage species [123,124]. ...
Survival and reproduction of several wild plants and crops is mostly by insects pollinator, their recognition and importance have been increased in this climatic changing scenario, which affects the various aspects of their life cycle. According to an estimate, approximately 30,000 species of bees are known in entomology, and about 190 species of bees have been reported to be associated with pollination. There can be an established link between seed production and pollinator diversity, for the plants with a generalist pollination system. The increasing of human habitation affects insect pollinators in various ways, i.e. of habitat destruction, results in low availability of food sources, nesting, oviposition, resting, and mating sites. Pollinator availability restraints the geographical distribution of plant species, i.e. to develop an ecological niche of certain plant species. Failure of pollinator-plant interaction mutualism results in lower seed production and sometimes extirpation of plant population has been recorded. The declining pollinators' population strengthens existing plant-pollinator interaction or allows new pant pollinator interaction to form. Maintaining the commercial and wild pollinator populations and preventing future shortages of pollination services, therefore, is extremely significant.
... Brooks et al. (2012) considered the loss of trees and hedgerows as the responsible factor that caused the decline of specialist ground beetles. The removal of weeds and trees may be the reason of the decline of some insect species overwintering in soil (Fox, 2013). ...
The diversity and abundance of insect is facing serious challenges globally in the current era. Although the loss of biodiversity other than invertebrates has been a burning issue from a long ago, some recent reports on insect decline and its impact on agriculture have given it a crucial dimension. Studies related to insect decline revealed that 40% of insect taxa are going through the risk of decline. The current situation is the resultant of several human-influenced factors, most prominently the intensification of agriculture. Insect is one of the most diverse groups having immense effects on ecosystem as an integral part of food web which ultimately has direct effect on other organisms of environment. The most conspicuous contribution of insect is its pollination services to 80% of the flowering plants worldwide which have direct effect on human food security. Decline of pollinator insects and natural enemies of insect pests can impair the crop production due to insufficient pollination and underutilization of the insect control potential of predator insects. To resist the vulnerability of nature and to ensure food security, insect decline should be cut down by controlling anthropogenic stressors through the conservation of natural habitats, eliminating deleterious agricultural practices, implementing insect friendly policies, etc. Immediate action is necessary to alter the nature exploiting agricultural practices causing insect decline to ensure the normal functioning and integrity of entire ecosystem and for human welfare.
... Lepidoptera is one of the most abundant and diverse insect orders, but is currently undergoing widespread declines across Europe (Fox, 2013). Previous studies at a national scale have demonstrated that managed coniferous plantation woodland / forestry plantations can support diverse invertebrate communities, and that the structure of the plantation is important for some groups (Humphrey et al. 2003). ...
Moths are a vital ecosystem component and key food source for many species, but have shown widespread and often severe declines. Multiple factors have been implicated in these declines, although the most important large-scale factors in the temperate zone are considered to be land use change and climate change. The majority of forest cover in the U.K. and elsewhere in Europe is dominated by intensively managed plantation woodlands, and studies have shown reduced broadleaved woodland cover can negatively affect moth diversity and biomass. However, few studies have examined how open habitats within the plantation forest matrix, which often represent a large proportion of the total forest area, are utilised by moth species. Here, we aimed to determine: (1) how moth biomass in open habitats within plantation forests varies seasonally and in response to management; and (2) how species diversity and Welsh conservation priority (“Section 7”) species respond to management at multiple spatial scales. We sampled moth communities in open habitats within five coniferous plantation forests across Wales, using light traps deployed in areas that ranged from < 1 to > 20 years post-felling. We found a significant non-linear relationship between space, time and moth biomass, with a significant peak in biomass in the summer months (∼29th June) suggesting important phenological effects with associated implications for dependent species. Biomass was also strongly affected by time since felling, with older habitats in general supporting a higher moth biomass, although this was dependent on the seasonal variation in habitat ‘greenness’ and productivity, as measured by NDVI. We also found that the abundances of Welsh priority species responded positively to increased extents of open habitats of ages 1–10 years post felling, but the amount of recent clear felling (0 years post felling) in the surrounding landscape had a negative correlation with both abundance and diversity. We conclude that habitat, seasonality/ productivity and short-term weather variations play a key role in determining moth biomass, species diversity and the presence of Welsh priority moth species within managed coniferous plantation woodland. This means there is an opportunity for forest management practices to adopt measures that can not only enhance moth biomass productivity, in turn supporting insectivorous species such as European nightjar Caprimulgus europaeus, but also deliver wider ecosystem services through the provision of habitat matrices that support invertebrate species of conservation concern.
World‐wide declines in arthropod abundance and diversity are a major concern, particularly given their importance in ecosystem functioning. Yet, data documenting long‐term trends are rare from the tropics, particularly the Afrotropics. Here we evaluate changes in the arthropod communities in Kibale National Park, Uganda across almost four decades. Systematic sweep‐net sampling was conducted in two forested sections of the park that had been logged and in one old‐growth forest area over 12 consecutive months in 1983/1984 and 2020/2021. This data was augmented with intermittent samples taken in 1986 and 1995. Arthropod abundance declined in all areas, but only significantly so in the moderately logged forestry compartment (41%). Permutational multivariate analysis of variance indicated that community compositions of arthropods differed between the censuses. Understanding the drivers of changes in the arthropod communities is difficult as the system is complex and dynamic. We document an increase in temperature, but no change in rainfall, increases in 11 mammal species, including a marked increase in elephant numbers, and changes in forest structure. We also report on changes in the landscape outside of the park, which includes the human population increasing by a factor of four and agricultural intensification that now includes the use of pesticides. We document that many components of the ecosystem we studied changed simultaneously, which signals that for effective conservation planning, more long‐term multi‐disciplinary efforts are needed. Sweep‐net sampling conducted in 1983/1984 and 2020/2021 document declines in arthropods by up to 41% and snails by up to 98%. We document potential drivers of this change, including an increase in temperature, increases in 11 mammal species, including a marked increase in elephant numbers, changes in forest structure, and marked increase in the human population outside the park that corresponded with agricultural intensification that now includes the use of pesticides
Montane species on islands attract attention due to their small and isolated populations and limited dispersal potential, making them vulnerable to extinction. We investigated the diversity pattern of moth assemblages over the 12-years-period (2009–2020) at 11 study plots on an island mountain (Mount Hallasan, Jeju-do Island, South Korea) to assess the changes in the moth assemblages in terms of species composition, richness, and abundances. We expected to find a decline in the number of species at these sites, given the reported decline in similar taxa in other temperate regions, such as Europe and North America. In contrast, we found that the numbers of species and individuals of moth populations on the island mountain have not significantly changed, except at the high-elevation sites, where the number of species has increased. Our results also show that the numbers of species and individuals are closely related to energy availability, actual evapotranspiration. Moreover, we found that the species composition during the study period has not been greatly changed, except at the lowermost and uppermost elevations. The mechanism driving this high dissimilarity of moth assemblages differed: the low-elevation site experienced high temporal turnover, and the high elevation sites also experienced high temporal turnover and nestedness resulting from active species replacement due to a recent forest fire and vegetation changes and the geographic and ecological constraints of the high elevations. To date, the moth species diversity of the temperate forests of the island mountain is not showing a drastic change. However, we observed that the moth assemblages had changed the number of species and individuals at low and high elevations. Given the biological and ecological limitations of moths (ectothermic organisms with limited habitat range) and considering the results of our study, we infer that climate change has impacted the diversity and species composition of moths on the island mountain.
One of the most dramatic changes occurring on our planet in recent decades is the ever-increasing extensive use of artificial light at night, which drastically altered the environment nocturnal animals are adapted to. One nocturnal species group experiencing marked declines are moths, which are not only of great importance for species conservation, but also for their key role in food webs and in ecosystem services such as nocturnal plant pollination. Light pollution has been identified as a driver in the dramatic insect decline of the past years, yet little is known about its impact on natural insect orientation behaviour. Using harmonic radar tracking, we show that the orientation of several species of moths is significantly affected by streetlights, although only 4 % of individuals showed flight-to-light behaviour. We reveal a species-specific barrier effect of streetlights on lappet moths whenever the moon was not available as a natural celestial cue. Furthermore, streetlights increased the tortuosity of flight trajectories for both hawk moths and lappet moths. Our results provide the first spatially resolved experimental evidence for the fragmentation of landscapes by streetlights and demonstrate that light pollution affects movement patterns of moths beyond previously assumed extend, potentially affecting their reproductive success and hampering a vital ecosystem service.
Agricultural intensification has led to a dramatic impoverishment of biodiversity. Moths are not an exception: rapid declines of common and widespread species have been reported and it is still not clear which conservation measures should be applied to restore their populations. We investigated how much of the variation in moth assemblages inhabiting extensively managed meadows in a region of high‐intensity agriculture is explained by surrounding woody landscape features, meadow management and vegetation composition, and which specific variables are the most influential. Results show that the percentage of forest and the length of hedgerows within a 250 m radius were especially important for forest macromoths, explaining 42% of variation in abundance and 23% of species richness, whereas meadow management played a relatively marginal role. The abundance of grassland macromoths was also positively influenced by the length of hedgerows in the landscape (combined with elevation it explained 10% of the variance), while it responded negatively to uncut refuge and to delayed mowing (7%). Regarding grassland macromoth species richness, the annual harvesting frequency was the main predictor (4%). In contrast, micromoth abundance was more influenced by meadow management, notably the date of the first cut (4%) and vegetation composition (8%, though not conclusive due to a single outlier), whereas landscape features explained nothing. Altogether, these results demonstrate the importance of both woody features within farmed landscapes and biodiversity‐friendly meadow management for the maintenance of integral moth communities. Macro‐ and micromoths were sampled in 47 extensively managed meadows located in a Swiss lowland region of high‐intensity agriculture. Altogether, results demonstrate that the preservation of integral moth communities within cultivated landscapes necessitates hedgerows and forest patches in complementation to grasslands that are extensively managed. More specifically, increasing the length of hedgerows within a 250 m radius would boost macromoth abundance and species richness (as shown in the figure).
Several hundred butterfly species show some form of migratory behaviour. Here we identify how the methodologies available for studying butterfly migration have changed over time, and document geographic and taxonomic foci in the study of butterfly migration. We review publications on butterfly migration published in six languages [English, Simplified Chinese, Traditional Chinese, Japanese, Korean, and Spanish], summarise how migration in butterflies has been studied, explore geographic and taxonomic patterns in the knowledge base, and outline key future research directions. Using English search keywords, we found only 58 studies from Asia; however, after searching in local languages, we found an additional 99 relevant studies from China, Japan, and Taiwan. Overall, butterfly migration studies are mostly concentrated in North America and Europe, with only 4.6% from Africa. Most studies focus on three species: monarch [Danaus plexippus], painted lady [Vanessa cardui] and red admiral [Vanessa atalanta]. About 62% of publications are focused on the monarch, with nearly 50% of migratory butterflies mentioned in no more than a single paper. Several research methods have been applied to ascribe migratory status and to study the physiology, neurobiology, and ecology of migration; however, virtually all this research is focused on a handful of species. There remain hundreds of species for which we do not understand the full seasonal pattern of movement, flight destinations, wintering, or breeding grounds. A full understanding of movement ecology and migratory connectivity is needed to effectively conserve migratory butterflies.
Concern for pollinator health often focuses on social bees and their agricultural importance at the expense of other pollinators and their ecosystem services. When pollinating herbivores use the same plants as nectar sources and larval hosts, ecological conflicts emerge for both parties, as the pollinator's services are mitigated by herbivory and its larvae are harmed by plant defences. We tracked individual-level metrics of pollinator health—growth, survivorship, fecundity—across the life cycle of a pollinating herbivore, the common hawkmoth, Hyles lineata , interacting with a rare plant, Oenothera harringtonii , that is polymorphic for the common floral volatile ( R )-(−)-linalool. Linalool had no impact on floral attraction, but its experimental addition suppressed oviposition on plants lacking linalool. Plants showed robust resistance against herbivory from leaf-disc to whole-plant scales, through poor larval growth and survivorship. Higher larval performance on other Oenothera species indicates that constitutive herbivore resistance by O. harringtonii is not a genus-wide trait. Leaf volatiles differed among populations of O. harringtonii but were not induced by larval herbivory. Similarly, elagitannins and other phenolics varied among plant tissues but were not herbivore-induced. Our findings highlight asymmetric plant–pollinator interactions and the importance of third parties, including alternative larval host plants, in maintaining pollinator health.
This article is part of the theme issue ‘Natural processes influencing pollinator health: from chemistry to landscapes’.
Declines and losses of insects throughout the world have wide ramifications for the sustainability of terrestrial and inland water ecosystems, and for humanity. Recent accounts and estimates of declines in insect richness and abundance in many parts of the world pose serious concerns for the future of global biodiversity. Some have been claimed to be sensationalistic and many such claims are difficult to validate. This summary of concerns demonstrates difficulties of interpreting data against insecure historical baselines and incomplete taxonomic and ecological information, features that introduce ambiguities and uncertainties in interpreting observed changes and may reduce credibility.
Animal behavior plays a critical role in conservation efforts. Efforts to captively breed endangered species hinge on understanding the species’ habitat requirements, mating behavior, and parent–offspring interactions. Conservation of species in the wild by creating sanctuaries is most successful if aspects of behavior such as territoriality, dispersal, and migration are factored into sanctuary design. Animal behavior gives biologists tools for measuring the level of disturbance that humans create for wild populations. Encroachment of humans into wildlife habitats makes human–wildlife interactions more frequent and behavior gives us clues about how to minimize negative impacts of humans on wildlife as well as how to help humans avoid injury when they encounter wildlife. Some species of wildlife have become more adept at living in towns and cities, bringing with them damage to landscaping, risk of disease spread, and in some cases risk of injury to humans or their companion animals. Animal behavior helps us to understand how to minimize these impacts and how to improve human–animal co-existence in urban and suburban settings. As human populations continue to expand and climate change impacts on wildlife intensify, knowledge of animal behavior will become increasingly important in conservation efforts.
Small Tortoiseshell numbers fell to unprecedented lows in the last few years. The recently arrived parasitoid Sturmia bella may be part of the problem but is not the sole factor driving the decline of this familiar and much-loved butterfly. Photograph Rachel Scopes 2 n The results show that the 2010 European Union target to halt the loss of biodiversity has not been met for the UK's butterflies. Ten-year trends show that 72% of species declined in abundance at monitored sites and that the UK distributions of 54% of butterflies also declined. Three-quarters of species showed a 10-year decrease in either their distribution or population levels. n Habitat specialist species have continued to decline and, for the first time, a significant decrease in overall numbers of wider countryside butterflies has also been recorded. Butterflies fared better in Scotland than in England, where there have been large population decreases in farmland and woodland habitats. n UK butterflies are thus still in serious decline and remain one of our most threatened wildlife groups in spite of increased conservation expenditure. Our results suggest that simple ecosystem-led approaches will not be effective in halting the decline of many specialist butterlies. A more targeted strategy is needed. n The ongoing deterioration of habitats is the main cause of these declines, resulting from inappropriate management (e.g. continued intensification or abandonment), insufficient quantity, quality or targeting of suitable conservation management and the effects of small habitat area and isolation. Highly variable summer weather may also be contributing, counteracting the mainly beneficial effects of climate warming.
Large declines in the breeding populations and contractions of breeding range have occurred in several woodland birds in Britain in recent decades. Data from the BTO's Common Birds Census indicate that 10 out of 32 woodland species declined by more than 50% between 1966 and 1999, while 5 species increased by more than 50% over the same period. The declining species differ substantially in their ecology and life-history patterns. No single general explanation can be identified for the declines and it is likely that multiple factors have exerted a combined effect on several of the species. Seven factors emerge from this review as especially relevant and worthy of further study: (i) pressures on migrants during migration or in winter; (ii) climate change on the breeding grounds; (iii) general reduction in invertebrate food supplies; (iv) impacts of land use on woodland edges, habitats adjacent to woodland and hedgerows; (v) reduced management of lowland woodland; (vi) intensified habitat modification by deer; and (vii) increased predation pressure from Grey Squirrels Sciurus carolinensis, Great Spotted Woodpeckers Dendrocopos major and corvids.
Butterflies and burnet moths are a suitable model species group with which to analyse the general decline of invertebrate biodiversity over the last few decades. In this study, we analysed which ecological groups of butterflies and burnet moths are most affected and how the recent modifications of the landscape have influenced them. Therefore, we studied the species composition of seven calcareous grassland remnants in south-western Germany in 1972 and 2001. We observed a strong change in the community composition and a severe decline in species richness. In general, the incidence of the autochthonous non-ubiquitous species declined by more than 50%, whereas ubiquitous species showed no significant difference in numbers during this period. Especially affected by the decline were those species which need structured habitats, those which are poor dispersers, species which need habitat sizes of 16 ha and more, monophagous species, K strategists and Red Data Book species. Most probably, either habitat outside the reserves is affecting dynamics within the reserves or loss of habitat outside the protected areas has reduced the overall area and connectivity of habitat for some species, increasing extinction rates and reducing colonisation rates in metapopulations. We conclude that these negative trends can only be stopped or even reversed if the landscape structure is made less hostile for species with conservation interest.
We illustrate the strong decrease in the number of butterfly species in Flanders (north Belgium) in the 20th century using data from a national butterfly mapping scheme. Nineteen of the 64 indigenous species went extinct and half of the remaining species are threatened at present. Flanders is shown to be the region with the highest number of extinct butterflies in Europe. More intensive agriculture practices and expansion of house and road building increased the extinction rate more than eightfold in the second half of the 20th century. The number of hot spots decreased considerably and the present-day hot spots are almost exclusively in the northeast of Flanders. Species with low dispersal capacities and species from oligotrophic habitats decreased significantly more than mobile species or species from eutrophic habitats. We discuss these results in a northwest European context and focus on concrete measures to preserve threatened butterfly populations in Flanders.
The bumble and cuckooo bees (Hymenoptera: Apidae: Bombini; Bombus spp. and Psithyrus spp., respectively) are important plant pollinators and any decline in numbers or species constitutes a significant threat both to biological diversity and to whole economies. The distribution, status and factors threatening all 60 known taxa (species and subspecies) of Bombini of 11 countries of Western and Central Europe (Belgium, the Netherlands, Luxembourg, Denmark, Germany, Switzerland, Austria, Czech Republic, Slovakia, Hungary, Poland) were assessed from the beginning of the 20th century. The analysis was based on a literature review, unpublished data, personal communications, our own observations, and an expert review. The IUCN Red List categories were used for assessing the threat of extinction. Eighty per cent of taxa were threatened in at least one country of the region, and 30% of taxa were threatened throughout their range in the countries considered. More species went extinct per country in the second than in the first half of the 20th century, and four taxa went extinct in all 11 countries during 1951–2000. Amongst the factors adversely affecting the Bombini anthropogenic factors (particularly those associated with large-scale farming schemes) appear to be of greater importance than natural factors. To halt population declines and species extinctions it will be necessary to preserve aspects of traditional farming practices and for all Bombini to be afforded legal protection in all countries of the region. The implementation of the European Union's Common Agricultural Policy is likely to have the greatest single impact upon pollinators in the near future.
The impact of non-native plant invasions on ecosystems has been controversial because obvious local effects have not yet led to the global extinction of any native plant species on continents and large islands. We suggest that extinction is not the appropriate measure of impact on ecosystem function and present evidence that non-native plant invasions or the replacement of native plants with non-native ornamentals results in significant bottom-up reductions of energy available for local food webs. Using replicated common gardens we compared Lepidoptera species richness and abundance on native plants, non-native congeners of those natives, and non-native species with no close relatives in the study area. Non-native plants supported significantly fewer caterpillars of significantly fewer specialist and generalist species even when the non-natives were close relatives of native host plants. However, the effect size was smaller in the latter category indicating phylogenetic similarity to local natives may positively impact herbivory. Cluster analysis revealed that a non-native plant congener often supports a lepidopteran community that is a subset of the similar, but more diverse community found on its native congener. The proportion of the Lepidoptera community consisting of specialist species was about five times larger across native species within sites compared to non-native plant species. In addition, species accumulation trajectories suggested that in a fully sampled community the differences between the Lepidoptera supported by native and non-native plants may be even greater than presented here.
Global climate change (GCC) significantly affects distributional patterns of organisms, and considerable impacts on biodiversity are predicted for the next decades. Inferred effects include large-scale range shifts towards higher altitudes and latitudes, facilitation of biological invasions and species extinctions. Alterations of biotic patterns caused by GCC have usually been predicted on the scale of taxonomically recognized morphospecies. However, the effects of climate change at the most fundamental level of biodiversity - intraspecific genetic diversity - remain elusive. Here we show that the use of morphospecies-based assessments of GCC effects will result in underestimations of the true scale of biodiversity loss. Species distribution modelling and assessments of mitochondrial DNA variability in nine montane aquatic insect species in Europe indicate that future range contractions will be accompanied by severe losses of cryptic evolutionary lineages and genetic diversity within these lineages. These losses greatly exceed those at the scale of morphospecies. We also document that the extent of range reduction may be a useful proxy when predicting losses of genetic diversity. Our results demonstrate that intraspecific patterns of genetic diversity should be considered when estimating the effects of climate change on biodiversity.
Evolutionary and population dynamics models suggest that the migration rate will affect the probability of survival in fragmented landscapes. Using data for butterfly species in the fragmented British landscape and in immediately adjoining areas of the European continent, this paper shows that species of intermediate mobility have declined most, followed by those of low mobility whereas high-mobility species are generally surviving well. Compared to the more sedentary species, species of intermediate mobility require relatively large areas where they breed at slightly lower local densities. Intermediate mobility species have probably fared badly through a combination of metapopulation (extinction and colonization) dynamics and the mortality of migrating individuals which fail to find new habitats in fragmented landscapes. Habitat fragmentation is likely to result in the non-random extinction of populations and species characterized by different levels of dispersal, although the details are likely to depend on the taxa, habitats and regions considered.
The book reviews the natural history of this generally little-known group (the Lepidoptera excluding butterflies), which comprises over 2000 species in the UK. After an introductory chapter, the author draws together the results of amateur study and the latest scientific research in chapters on: the origins and distribution of Britain's moths; dispersal, migration and orientation; life cycles and hibernation; plants as food for moths; plant defence against larvae; mating behaviour and the use of pheromones in the control of moth pests; moth predators and population dynamics; catching and studying moths; and the conservation of moths. Numerous examples of spcies studies from the scientific literature are included to illustrate aspects such as distributions, subspecies, races and clines, orientation cues, mass migrations, strategies for emergence from pupae, feeding strategies, responses to chemical defence, predator avoidance, crypsis and mimicry, and endangered species and species undergoing conservation action.
Summary Plant introductions to the British Isles can be divided into those introduced before 1500, the ‘archaeophytes’, numbering c. 150 species and considered in Chapter 35, and those introduced later, the ‘neophytes’. The neophytes comprise a very large number in total, but with about 230 species having spread far from their original introduction site. Most neophytes have spread in the twentieth century. A remarkable number spread mainly or entirely by vegetative means. Neophytes occur throughout the British Isles, but are most common in disturbed sites and especially in south-east England. Certain neophytes have a particularly interesting historical distribution or exhibit taxonomic and ecological problems that have generated much research. Freshwater habitats contain several fast spreading and abundant neophytes that spread vegetatively. Most neophytes are attractive insect-pollinated plants introduced initially for their ornamental qualities and, though they can become abundant in places, do not pose ecological problems. Examples are the Ivy-leaved Toadflax, some bellfowers and the Buddleia. They are broadly welcomed. A few have invaded sensitive habitats, but widespread ‘problem’ plants are very few in number: Japanese Knotweed, ‘Wild’ Rhododendron, New Zealand Pigmyweed, Himalayan Balsam and in a few places Hottentot Fig; maybe one or two others locally. The widespread planting of trees, both native and non-native, and the spread of ‘wild flower mixes’ for roadside and meadow plantings has led to some mixing of native and non-native genetic material. Most of these have become inextricably mixed. […]
Summary Over the last 50 years, the human population of the UK (Britain and Northern Ireland, excluding overseas territories) has both expanded and become substantially more urbanised. The consequences for wildlife have undoubtedly been complex, with the low priority that has been given to monitoring schemes in urban environments compounding the difficulty in drawing overall conclusions. Nonetheless, it is clear that substantial areas of natural and semi-natural habitats have been lost, and that the richness and abundance, particularly of more specialist and previously narrowly distributed species associated with these habitats, have declined. Conversely, some more generalist species have greatly benefited, as have others that could exploit some of the more novel environments occurring in urban areas. Moreover, urban areas have become more significant for wildlife over the past 50 years, in large part because they figure more prominently in landscapes, because of a marked increase in awareness of and conservation efforts for urban biodiversity, and because urban areas hold a substantial proportion of the national populations of some species that have experienced dramatic declines in the wider countryside. Introduction Over the last 50 years the human population of the UK has grown by more than 15% (Figure 6.1; from 52.8 million in 1961 to 60.6 million in 2006; National Statistics 2007a). The annual growth rate has been an order of magnitude higher in urban areas than in rural ones, such that over 90% of the population now lives in the former.
Summary Invasive alien species are, after habitat loss, the principal factor in the decline or extinction of native organisms. The Wildlife and Countryside Act 1981 and the Wildlife (Northern Ireland) Order 1985 prohibit the future introduction and release into the wild of non-native species in Britain and Northern Ireland. Corresponding legislation in the Republic of Ireland is the Wildlife Act 1976 and the European Communities (Natural Habitats) Regulations 1997. The European Union Habitats and Species Directive requires member states to restore natural biodiversity, whenever practicable, by reintroducing formerly native species that have become extinct. Whereas, in times past, the practice of introducing exotics was acceptable, now the reintroduction of former native species is seen as the way forward. Introduction The impact of invasive alien species on native fauna and flora is, after habitat destruction, the most important factor in the decline or extinction of indigenous organisms. Arguably the most significant single factor affecting introduced species in Britain during the past half century has been the enactment of the Wildlife and Countryside Act 1981. Hitherto, those wishing to release exotic species into the wild had what amounted to virtually a free hand. Section 14 Part I of this Act lays down that: (1) Subject to the provisos of this Part, if any person releases or allows to escape into the wild any animal which (a) is of a kind which is not ordinarily resident in and is not a regular visitor to Great Britain in a wild state; or (b) is included in Part I Schedule 9, he shall be guilty of an offence.
Summary Moths are a diverse group of insects (around 2500 species in Britain and Ireland) that make a significant contribution to our biodiversity. Despite being a species-rich group, the popularity of moth recording has made it feasible to assess rates of species colonisation and local extinction, conservation status and, for hundreds of macro-moth species, long-term population trends in Britain. The moth fauna of Britain is constantly changing, with small numbers of species colonising the country or becoming extinct each decade. Set against this small turnover of species is the dramatic evidence of a severe decline in moth numbers, most notably in the south-east of Britain. The unique monitoring data available from the Rothamsted light-trap network show that the total number of moths captured nationally declined by almost a third between 1968 and 2002, although there was no overall decline evident in northern Britain. Two-thirds of the 337 individual species of common larger moth examined in detail had declined in abundance during that period. Over 20% of these common species have decreased so severely that they qualify as nationally threatened species under internationally recognised criteria. Such widespread declines are likely to have serious detrimental knock-on effects on other organisms and signal a wider biodiversity crisis. Introduction The significance of moths Moths are one of the largest insect groups both in Britain and globally, and thus make up a significant part of our biodiversity. About 2500 species have been recorded in Britain and Ireland.
These proceedings contain papers on insect conservation biology that are classified under 3 themes: (1) the current status of insect conservation, and major avenues for progress and hindrances (6 papers); (2) insects as model organisms in conservation biology (6 papers); and (3) future directions in insect conservation biology (6 papers).
The populations of farmland birds in Europe declined markedly during the last quarter of the 20th century, representing a severe threat to biodiversity. Here, we assess whether declines in the populations and ranges of farmland birds across Europe reflect differences in agricultural intensity, which arise largely through differences in political history. Population and range changes were modelled in terms of a number of indices of agricultural intensity. Population declines and range contractions were significantly greater in countries with more intensive agriculture, and significantly higher in the European Union (EU) than in former communist countries. Cereal yield alone explained over 30% of the variation in population trends. The results suggest that recent trends in agriculture have had deleterious and measurable effects on bird populations on a continental scale. We predict that the introduction of EU agricultural policies into former communist countries hoping to accede to the EU in the near future will result in significant declines in the important bird populations there.
1. The historical role of agriculture in creating semi-natural vegetation is still not fully appreciated by many ecologists, conservationists, policy-makers or the general public. Nor is the fact that for many European landscapes and biotopes of high nature conservation value, the only practicable, socially acceptable and sustainable management involves the continuation of low-intensity farming. Consequently, too much emphasis is placed on attempting to ameliorate damaging effects of agricultural management rather than supporting ecologically sustainable low-intensity farming practices. 2. More than 50% of Europe's most highly valued biotopes occur on low-intensity farmland. However, most of this farmland has no environmental policy directly affecting it; most management decisions are taken by farm businesses and determined primarily by European and national agricultural officials. As a result, there continues to be intensification or abandonment of traditional practices, changes which are equally damaging to the nature conservation value. 3. However, the nature conservation importance of low-intensity farming systems is gradually being recognized. Reforms and reviews of agriculture policy are providing a variety of potential opportunities for maintaining such systems. Unfortunately, initiating change through policy is a slow process. There is therefore also a pressing need to look for other opportunities to maintain surviving systems and, where possible, to reinstate those recently lost. 4. Although these systems may be considered low-intensity in terms of chemical inputs and productivity, they are usually high-intensity in terms of human labour. Therefore, the processes that make the low-intensity farmed countryside biologically rich and diverse must be understood, but at the same time mechanisms to make life easier and more rewarding for the people who work such farmland must be found. 5. Ecologists and conservationists should think less of 'remnants of habitat being left amongst farmland' and more of a farmland biotope for which optimum management practices need to be developed. At the same time the current emphasis on site-based conservation should be complemented by strategic initiatives that promote wise management of the wider countryside.
Abstract? Biodiversity, a central component of Earth's life support systems, is directly relevant to human societies. We examine the dimensions and nature of the Earth's terrestrial biodiversity and review the scientific facts concerning the rate of loss of biodiversity and the drivers of this loss. The estimate for the total number of species of eukaryotic organisms possible lies in the 5?15 million range, with a best guess of ?7 million. Species diversity is unevenly distributed; the highest concentrations are in tropical ecosystems. Endemisms are concentrated in a few hotspots, which are in turn seriously threatened by habitat destruction?the most prominent driver of biodiversity loss. For the past 300 years, recorded extinctions for a few groups of organisms reveal rates of extinction at least several hundred times the rate expected on the basis of the geological record. The loss of biodiversity is the only truly irreversible global environmental change the Earth faces today.
1. The abundance and species richness of butterflies on expanded-width uncropped arable field edges, which were subject to 10 contrasting, experimental management regimes, were measured using transects in 1989, 1990 and 1991. The effects of the management regimes on a number of botanical variables, likely to be of importance to butterflies, were measured. 2. On the experimental field edges, butterfly abundance and species richness fluctuated between years and peaked at different times each year. 3. Butterfly abundance and species richness differed between experimental treatments. Plots which were either cut in the spring and autumn, or not cut at all, attracted more individuals and species of butterfly than did plots cut in the summer. Sowing with a grass and wild flower seed mixture increased butterfly abundance. Butterfly abundance declined on swards sprayed once annually with herbicide. 4. Mowing, sowing and spraying had significant effects on mean flower abundance, on the annual and perennial components flowering in the sward, and on the abundance of commonly used nectar sources and larval host-plants. 5. Stepwise multiple regression analyses on butterfly and plant data showed that the abundance of adults of most butterfly species was most closely associated with the abundance of flowers of key nectar source species. 6. The results are discussed in relation to resource provision for larval and adult butterfly stages. Recommendations (emboldened in the text) are made for the conservation management of butterflies on arable farmland.
These proceedings contain papers on insect conservation biology that are classified under 3 themes: (1) the current status of insect conservation, and major avenues for progress and hindrances (6 papers); (2) insects as model organisms in conservation biology (6 papers); and (3) future directions in insect conservation biology (6 papers).
Aim An increase in multivoltinism in ectothermic animals has been proposed by several authors as a possible outcome of climate warming, especially in high latitudes. We tested this prediction with large-scale empirical monitoring data for boreal moth communities.
Location Finland, northern Europe.
Methods Our data set comprised observations of multivoltine species made in the Finnish moth monitoring scheme ‘Nocturna’ trap sites during the period 1993–2006 along an exceptionally long latitudinal gradient of 1000 km. To compare recent changes in moth multivoltinism with a longer time period, we gathered older time series of moth observations from five locations. We used generalized linear mixed models (GLMMs) to detect possible temporal and geographical trends in the annual occurrence of multivoltinism. We also identified areas where the recent changes in multivoltinism have been greatest. Monthly average temperatures of spring and summer periods and annual sum of growing degree days above 5 °C (GDD5) were used as explanatory variables to distinguish the main climatic correlates of moth multivoltinism.
Results We observed a clear increase in the occurrence of moth multivoltinism during the period 1993–2006. The incidence as well as the recent increase in multivoltinism were highest in southernmost Finland and decreased towards the north. We also detected a weaker, although significantly positive, trend of moth multivoltinism in southern Finland during the period 1963–92, suggesting that this increasing trend might already have begun earlier. The most important climatic correlates for the annual occurrence of moth multivoltinism were the mean summer temperature (periods May–July and June–August) and GDD5, but all the tested climatic variables showed a significant univariate relationship with the occurrence of moth multivoltinism. All climatic variables showed an increasing trend during the period 1993–2006.
Main conclusions The occurrence of multivoltinism has increased in northern European moth communities during recent decades, apparently as a response to increasing temperatures during the spring and summer seasons. The increase in multivoltinism was greatest in the southernmost parts of Finland, whereas in the northern landscapes recent warming has triggered multivoltinism in only relatively few moth species.
Most extinctions estimated to have occurred in the historical past, or predicted to occur in the future, are of insects. Despite this, the study of insect extinctions has been neglected. Only 70 modern insect extinctions have been documented, although thousands are estimated to have occurred. By focusing on some of the 70 documented extinctions as case studies, I considered ways in which insect extinctions may differ from those of other taxa. These case studies suggested that two types of extinction might be common for insects but rare for other taxa: extinction of narrow habitat specialists and coextinctions of affiliates with the extinctions of their hosts. Importantly, both of these forms of extinction are often ignored by conservation programs focused on vertebrates and plants. Anecdotal evidence and recent simulations suggest that many insect extinctions may have already occurred because of loss of narrow habitat specialists from restricted habitats and the loss of hosts. If we are serious about insect conservation, we need to spend more time and money documenting such extinctions. To neglect such extinctions is to ignore the majority of species that are or were in need of conservation.
During the last decades, artificial night lighting has increased globally, which largely affected many plant and animal species. So far, current research highlights the importance of artificial light with smaller wavelengths in attracting moths, yet the effect of the spectral composition of artificial light on species richness and abundance of moths has not been studied systematically. Therefore, we tested the hypotheses that (1) higher species richness and higher abundances of moths are attracted to artificial light with smaller wavelengths than to light with larger wavelengths, and (2) this attraction is correlated with morphological characteristics of moths, especially their eye size. We indeed found higher species richness and abundances of moths in traps with lamps that emit light with smaller wavelengths. These lamps attracted moths with on average larger body mass, larger wing dimensions and larger eyes. Cascading effects on biodiversity and ecosystem functioning, e.g. pollination, can be expected when larger moth species are attracted to these lights. Predatory species with a diet of mainly larger moth species and plant species pollinated by larger moth species might then decline. Moreover, our results indicate a size-bias in trapping moths, resulting in an overrepresentation of larger moth species in lamps with small wavelengths. Our study indicates the potential use of lamps with larger wavelengths to effectively reduce the negative effect of light pollution on moth population dynamics and communities where moths play an important role.