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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.
... While these topics have not been investigated in moths, they are known drivers behind butterfly declines Inamine et al. 2016). Nevertheless, moths are declining globally in response to multiple anthropogenic stressors, with the direct and indirect effects of climate change playing a major role Fox 2013;Fox et al. 2014;Boyes et al. 2021;Blumgart et al. 2022). Since moth declines represent the loss of both a large portion of biodiversity, and important ecosystem functions and services, conserving them should be a top priority. ...
... This is problematic because moths face many of the same threats as diurnal pollinators, in addition to unique ones such as light pollution Boyes et al. 2021;Grenis et al. 2023). Consequently, moths are declining in richness and abundance globally Fox 2013;Habel et al. 2019;Salcido et al. 2020;Burner et al. 2021;Blumgart et al. 2022). In the Northeastern US, for example, 44% of hawkmoth (Sphingidae) species declined from 1900 to 2012 . ...
... Lepidoptera (butterflies and moths) are one of the most diverse insect orders (Scoble 1992;Wahlberg et al. 2013;Goldstein 2017), and are suffering some of the steepest declines among insect groups in part due to specialized food and habitat requirements and temperaturesensitive life stages (Wilson & Maclean 2011;Fox 2013;Fox et al. 2014;Maurer et al. 2018;). In the US, for example, Western butterfly abundance has declined by an average of 1.6% per year over the last four decades . ...
Anthropogenic global climate change can disrupt plant-pollinator interactions by altering the traits, phenologies, and distributions of interacting species, exacerbating insect declines and compromising ecosystem function. However, most research has focused on diurnal pollinators, and little is known about the prevalence, importance, and vulnerability of nocturnal moth pollination. This knowledge gap limits our ability to predict and mitigate the effects of climate change and other stressors on moths and their pollination services. In this dissertation, I investigate the ecology of moth pollination interactions, how moths and their host and nectar plants will be impacted by climate change, and how to apply this knowledge in conservation strategies. I focus on native plants and moths in California, a biodiversity hotspot that is particularly impacted by climate change. I employ techniques ranging from greenhouse experiments to DNA metabarcoding to explore impacts spanning the levels of functional traits to ecological networks. In Chapter 1, I document hundreds of previously undescribed moth pollen-transport interactions along an elevational gradient spanning desert to conifer forest. I also find that moths are smaller, less diverse, and more sensitive to the simulated loss of their nectar plants in hotter and drier conditions. In Chapter 2, I reveal that experimental warming and drought alter diel patterns of floral nectar quantity and quality in a generalist plant. This may differentially affect interactions with diurnal and nocturnal pollinators, scaling up to alter the structure and stability of plant-pollinator interaction networks. In Chapter 3, I analyze and compare Lepidoptera-host and -nectar plant interaction networks across California, revealing structural differences and spatial patterns that inform management priorities. I also analyze species roles in networks to identify spatially-explicit keystone plant species to be used in butterfly and moth conservation efforts. Together, my results reveal that moth pollination interactions are diverse, complex, and vulnerable to climate change, and that data-driven conservation strategies can help protect them. Ultimately, this dissertation highlights the importance of considering the nocturnal components of plant-pollinator networks in research and management.
... Lepidoptera is the most threated insect order due to human activities (Box 10.1) (Dirzo et al. 2014;Wagner 2020). Several studies have pointed to its sharp decline in several European countries and in North America, driven mainly by the expansion of agricultural activities (Conrad et al. 2004(Conrad et al. , 2006Fox 2013;Fox et al. 2015;Habel et al. 2019;Mattila et al. 2006;Wagner 2020). Although insect responses to climate change are biased due to an overrepresentation of studies involving lepidopterans (Dirzo et al. 2014;Wagner 2020), similar patterns of decline have been observed in other orders such as Coleoptera, Hymenoptera, Orthoptera and Odonata, with habitat loss also being the main reason for the decline (Dirzo et al. 2014; Sánchez-Bayo and Wyckhuys 2019). ...
... The most complete studies on the decline of insects due to habit loss and climate change are those carried out with lepidopterans and offer the richness and depth of studies over time. Among these, several point to a severe decline of the group due to habitat loss, climate change and pollution (Conrad et al. 2004(Conrad et al. , 2006Fox 2013;Fox et al. 2015;Habel et al. 2019;Mattila et al. 2006;Wagner 2020). However, some have also pointed out that some lepidopterans may not be affected by these effects or even benefit from these changes (Halsch et al. 2021;Lamarre et al. 2022;). ...
... Thus, while van Klink et al. (2020) showed that terrestrial insects are declining and aquatic insects are increasing in number, Sánchez-Bayo and Wyckhuys (2019) point to a general decline in insect population overall. Several studies point to a high decline in the order Lepidoptera (Conrad et al. 2004(Conrad et al. , 2006Fox 2013;Fox et al. 2015;Mattila et al. 2006), but in some regions populations have remained constant . Furthermore, species living in different environmental gradients show different responses to changes in the environment (Halsch et al. 2021), and something similar has been observed in both generalist and specialist species (Powney et al. 2019). ...
Climate change is ten times faster now than in the last global warming event, 56 million years ago, with temperature and extreme weather dramatically increasing due to human activity. This rapid changes in climate affect all levels of biodiversity. However, despite their high global biodiversity, only 3 percent of global climate change literature is based on invertebrates. Evidence from the fossil record has revealed low extinction rates for insect families in past catastrophic global events and omic sciences have allowed a much deeper understanding of the insect physiological and phenological responses to heat and their genetic basis. Insects acclimate and adapt to climate change, but several fail and suffer important reductions in population sizes besides local and global extinctions. The challenge is mainly driven by climate change potentiating the negative effects of other stressful conditions such as deforestation and pollution. Some species, notably pests and vectors, benefit from current climate change and either expand their distribution ranges or invade new environments. Moreover, biotic interactions involving insects and other organisms are threatened by climate change, generating cascading effects and affecting ecosystem functions and human wellbeing. Refugia from climate change across continents are fundamental for insects to withstand climate change and are of priority protection. This book provides key reflections regarding what we know and ignore about insect physiology, evolution, ecology and conservation and concludes by identifying fundamental aspects that still limit our understanding of how insects respond to climate change.
... Moths provide important ecological services such as pollinators, prey, and defoliators and yet they are greatly understudied (Slade et al. 2013, Fox 2013. They are the largest group of pollinators comprising of more than 1,300 species in the state of Nebraska and around 20,000 in North America north of Mexico (Dankert n.d.). ...
... Various rare vascular plants, such as the western prairie fringed orchid (Platanthera praeclara), depend on these moths to support future generations (Westwood andBorkowsky 2004, Young et al. 2017). Moths also serve as an important food source to many birds, bats, herptiles, small mammals, and predatory arthropods (Hammond and Miller 1998, Slade et al. 2013, Fox 2013. Conversely, they are prominent defoliators and consume high proportions of foliage (Slade et al. 2013, Fox 2013, Hammond and Miller 1998. ...
... Moths also serve as an important food source to many birds, bats, herptiles, small mammals, and predatory arthropods (Hammond and Miller 1998, Slade et al. 2013, Fox 2013. Conversely, they are prominent defoliators and consume high proportions of foliage (Slade et al. 2013, Fox 2013, Hammond and Miller 1998. As significant pollinators, prey, and defoliators, they can affect plant population dynamics, predator-prey population dynamics, nutrient cycling, and microclimates (Brookes et al. 1987, Gange and Brown 1989, Elkinton and Liebhold 1990, Huntly 1991, Campbell 1993, Hammond and Miller 1998. ...
Numerous conservation and surveying efforts have been aimed toward assessing and documenting pollinators in decline, including bees and butterflies, across North America. However, less knowledge and study have been geared toward the often overlooked and seldom inventoried nocturnal moth species, which also provide important ecosystem services such as pollination. As a diverse group of pollinators, prey, and defoliators, moths are not represented adequately in ecological research. The purpose of our study was to identify the species of moths present on Platte River Whooping Crane Maintenance Trust Inc. (Crane Trust) properties, which are located within the Central Platte River Valley (CPRV) in Nebraska. We conducted an investigation that included 17 sites with various landcover types, land-use histories, and anthropogenic disturbance levels over a six-week period between June 8 and July 20, 2022 and on September 19 and 20, 2022. In an effort to attract a wide variety of species, we used a UV light trap and a fermented fruit lure to attract moths and surveyed 30 minutes to 5 hours after civil twilight. Our UV light trap was successful in helping us capture and identify 235 nocturnal moth species including 12 species newly recorded in the state of Nebraska. Our fermented fruit lure was not as effective and attracted only six moth species, all of which were detected at our light trap. Our findings contribute to the understanding of many species’ ranges and are an indication of the great diversity of moths present within the CPRV. A full examination of the differences in species composition and richness between landcover types, land-use histories, and anthropogenic disturbance levels would be a worthwhile task. However, it would require further research that would involve multiple visits to each site and a survey period that extends from early June through late September to obtain species presence data that is more representative of the entire moth community.
... Dosedanje raziskave v evropskem prostoru vsaj posredno kažejo na zmanjševanje pestrosti metuljev zaradi svetlobnega onesnaževanja (Conrad et al. 2006, Mattila et al. 2006, Groenendijk & Ellis 2010, Fox 2012, vendar je učinke le-tega težko ločiti od upadanja pestrosti zaradi izgube habitata, ki je še vedno najpomembnejši dejavnik ogrožanja biodiverzitete na splošno. V Slovenije je to prva tako obsežna raziskava, ki kaže, da svetlobno onesnaževanje vpliva na veliko število vrst nočnih metuljev, ki so tudi zaradi vrstne pestrosti ena izmed najpomembnejših skupin v prehranjevalnih spletih, pomembni pa so tudi kot opraševalci (van Langevelde et al. 2011, Fox 2012. ...
... Dosedanje raziskave v evropskem prostoru vsaj posredno kažejo na zmanjševanje pestrosti metuljev zaradi svetlobnega onesnaževanja (Conrad et al. 2006, Mattila et al. 2006, Groenendijk & Ellis 2010, Fox 2012, vendar je učinke le-tega težko ločiti od upadanja pestrosti zaradi izgube habitata, ki je še vedno najpomembnejši dejavnik ogrožanja biodiverzitete na splošno. V Slovenije je to prva tako obsežna raziskava, ki kaže, da svetlobno onesnaževanje vpliva na veliko število vrst nočnih metuljev, ki so tudi zaradi vrstne pestrosti ena izmed najpomembnejših skupin v prehranjevalnih spletih, pomembni pa so tudi kot opraševalci (van Langevelde et al. 2011, Fox 2012. Posledično ima lahko upad njihove številčnosti velik vpliv na ekosisteme kot celota, v končni fazi tudi na ljudi, ki so vezani na opraševalce kulturnih rastlin. ...
... This is the first comprehensive survey of impact of artificial illumination on moths in Slovenia and shows that light pollution affects a large number of moth species. Due to large moth diversity and their important role in food webs and as pollinators (van Langevelde et al. 2011, Fox 2012, their decline could consequently have negative impacts on the ecosystems as a whole. To avoid contiguous deterioration of the habitat quality, it would be advisable to enforce a more rigorous legislation that would prevent the use of lamps with short-wave light in public lighting, in particularly in protected areas such as Natura 2000 sites (UL RS 49/2004), which are intended for the conservation of moths. ...
Negativni vpliv svetlobnega onesnaževanja na nočne metulje je znan, vendar premalo raziskan pojav. V letih 2011–2013 smo na 15 izbranih cerkvah v različnih biogeografskih regijah Slovenije in na Koči na Sabotinu preučevali nočne metulje na osvetljenih delih fasad. Skupno smo zabeležili 609 vrst nočnih metuljev, kar je približno 20 % vseh v Sloveniji živečih vrst metuljev. Največ vrst je bilo najdenih na Koritnem na Pohorju (214 vrst) in na Koči na Sabotinu (213 vrst). Na tej lokaciji je bilo ugotovljenih tudi največ ogroženih vrst metuljev v Sloveniji, in sicer osem od skupno 18 vrst. Glavni razlog za takšen odklon je ohranjenost habitatov v okolici osvetljenega objekta, deloma pa tudi dejstvo, da tu ni bilo svetlobnega onesnaževanja, saj objekt pred raziskavo ni bil nikoli osvetljen. Ugotavljamo, da svetlobno onesnaženje privablja veliko število vrst nočnih metuljev, zato bi ga bilo treba ustrezno omejiti; tako z ustrezno zakonodajo kot tudi v praksi. V prispevku podajamo natančnejše podatke o razširjenosti nekaterih redkih vrst, zbranih pred in med to raziskavo.
... Accelerating habitat loss and degradation due to anthropogenic activities is one of the major threats to the long-term persistence of Lepidoptera-butterflies and moths (Fox, 2012;van Swaay et al., 2010;Wagner et al., 2021). The proportions of threatened species and rates of decline in insects are suggested to approach or exceed those of vertebrates (Dirzo et al., 2014;Thomas et al., 2004), and several regional extinctions of lepidopterans have been documented in Europe and USA (Feltwell, 1995;New, 2012). ...
... Many species have restricted ranges and small populations, and poor habitat connectivity further reduces both abundance and species richness (Brückmann et al., 2010). Ongoing dramatic declines reported across Europe (Fox, 2012;Habel et al., 2016;Kurze et al., 2018;Warren et al., 2021), North America (Forster et al., 2011;Van Deynze et al., 2024;Wepprich et al., 2019) and Asia (Choi et al., 2017;Nakamura, 2011) all indicate that future conservation cannot rely solely on habitat restoration and management, but will increasingly need to include population reinforcements or reintroductions (reviewed in Schultz et al., 2008). ...
Many Lepidoptera species are declining to the point that active measures such as reinforcements and reintroductions are necessary to maintain viable populations. To maximise success of such efforts, we need to understand the factors influencing habitat preferences for oviposition.
In a Swedish island population of the red‐listed chequered blue butterfly (Scolitantides orion), we characterised oviposition preference by documenting whether the presence and abundance of eggs (i) increased with size and local density of its host plant, orpine (Hylotelephium telephium), and (ii) was associated with nectar plant abundance, degree of shading, and ground cover composition within small and large circular plots (1 m vs. 5 m radius) around focal plants. To reinforce a tiny population on a neighbouring island, we released 127 pupae and 46 imagos and recorded oviposition for two seasons.
The probability of receiving eggs increased with focal host plant size, and also with mean size of other host plants and cover of lichens within the large plots. The abundance of eggs within large plots increased with host plant density and amount of lichen cover. Habitat characteristics of the large plots predicted oviposition better than did those of small plots, and both outperformed models including host plant size only.
In the reinforcement population, all released pupae eclosed, and we found a total of 507 eggs on 272 host plants during the release season. Eggs were present on 5% of examined host plants, and median distance to a release spot was 19.3 m. In the following year, we found 420 eggs on 209 plants, and median distance to a release spot increased to 35.7 m, indicating diffusion through the habitat.
Practical implication. The chequered blue butterfly prefers to oviposit on large host plants in patches with high host density and high cover of lichens. To identify suitable release habitats, environmental conditions should be considered in an area of ca 80 m². The reinforcement shows that small releases can be successful and suggests that similar low‐effort approaches can be effective to boost local populations of many threatened butterflies, provided suitable habitats are available.
... Moths and butterflies are known to be vulnerable to habitat loss due to their unique host plant adaptation system [34]. Lepidoptera species are widespread and play important roles in ecosystem services and management [35]. ...
... A previous report in Malaysia revealed a 19% reduction in the moth population at Mount Kinabalu due to agricultural intensification and pesticide use ( Table 2) [47]. In Great Britain, a previous study showed 28% decrease in larger moth total abundance [34]. Burnet moths also decreased from 117 species to 71, with most of them considered highly endangered in Germany [48]. ...
As agricultural production increases, the use of chemical fertilisers, herbicides, and other synthetic pesticides has equally increased over the years. Inadequate pesticide application description and monitoring has generated a heated debate among governmental organisations, agricultural industries, and conservation organisations about pesticide effects on insect species richness and abundance. This review is therefore aimed at summarizing the decline in insects’ species and individual numbers as a result of extensive pesticide utilisation and recommends possible management strategies for its mitigation. This review revealed an average pesticide application of 1.58 kg per ha per year, 0.37 kg per person per year, and 0.79 kg per USD 1000 per year. Insects have experienced a greater species abundance decline than birds, plants, and other organisms, which could pose a significant challenge to global ecosystem management. Although other factors such as urbanisation, deforestation, monoculture, and industrialisation may have contributed to the decline in insect species, the extensive application of agro-chemicals appears to cause the most serious threat. Therefore, the development of sustainable and environmentally friendly management strategies is critical for mitigating insect species’ decline.
... For moths, quantitative estimates are only available for Great Britain and the Netherlands, but these also indicate substantial losses in both abundance and species richness. Thus, a 31% loss in abundance has been reported for Great Britain over a 35-year period, with declining population trends for 66% of the 337 species studied (Fox, 2013). In the Netherlands, Groenendijk & Ellis (2011) found similar changes, with 71% of 733 Dutch macro-moth species decreasing in abundance and the total abundance of moths decreasing by one-third over the period 1980-2009. ...
... The concern for Lepidoptera as non-target organisms is justified by the strong declines that are being recorded, both in butterflies (Van Swaay et al., 2010; and macro-moths (Groenendijk & Ellis, 2011;Fox, 2013). Even common species are seen to decline (Van Dyck, et al., 2009). ...
CG M 2 017-03 O n de r zOek sr a p p O r t The importance of maize and oilseed rape field margins for Lepidoptera Cover photograph by Sergej Jansen: the Dusky Large Blue (Phengaris nausithous), a critically endangered butterfly in the Netherlands, with a substantial occurrence in maize field margins.
... Across beetle families (Hallmann et al., 2020;Harris et al., 2019), and more specifically for Carabids (Brooks et al., 2012;Homburg et al., 2019) and a Cerambycid (Baur et al., 2020), declining patterns with time have been reported. The same was true for Hymenopterans (Bartomeus et al., 2019;Ollerton et al., 2014) and Lepidopterans, especially for moths (Bell et al., 2020;Fox, 2013;Fox et F I G U R E 4 Response curves of significant predictors for total morphospecies richness (blue), abundance (orange) and biomass (green). f shows the response curve of the predictor. ...
... Across beetle families (Hallmann et al., 2020;Harris et al., 2019), and more specifically for Carabids (Brooks et al., 2012;Homburg et al., 2019) and a Cerambycid (Baur et al., 2020), declining patterns with time have been reported. The same was true for Hymenopterans (Bartomeus et al., 2019;Ollerton et al., 2014) and Lepidopterans, especially for moths (Bell et al., 2020;Fox, 2013;Fox et F I G U R E 4 Response curves of significant predictors for total morphospecies richness (blue), abundance (orange) and biomass (green). f shows the response curve of the predictor. ...
While many studies on insect diversity report declines, others show stable, fluctuating or increasing trends. For a thorough understanding of insect trends and their effects on ecosystem functioning, it is important to simultaneously assess insect richness, abundance and biomass, and to report trends for multiple taxa.
We analysed insect richness, abundance and biomass data for all insects and for eight insect taxa (Buprestidae, Cerambycidae, Carabidae, other Coleoptera, Aculeata, other Hymenoptera, Heteroptera and Lepidoptera) from 42 sites across Switzerland from 2000 to 2007, representing three major habitat types in Switzerland (agricultural, unmanaged [open and forested] and managed forest habitats). As potential drivers of temporal patterns, we evaluated weather‐ and land‐use‐related factors. As predictors, we included temperature and precipitation as well as the vegetation index and the habitat type, respectively.
We found a consistent pattern of stable or increasing trends for richness, abundance and biomass of insects in total and the eight taxa over 8 years. Both overall patterns and six out of eight taxa (except for Cerambycidae and Lepidotpera) showed the highest values in agricultural habitats. However, when accounting for elevation, there was no difference in open habitats regardless of whether they were used agriculturally.
Habitat types were the most important predictors, followed by weather‐ and vegetation‐related factors. Modelled responses to mean temperature were unimodal, whereas the standard deviation of temperature showed positive and precipitation negative effects. Longer time series are needed to draw robust inferences and to investigate potential negative effects of future warming.
... Tragically, nocturnal moth populations have declined by an overwhelming two-thirds since the early 1970s (Fox et al., 2013). In addition to climate change and habitat degradation, the available evidence strongly suggests that ALAN may be driving population decreases in Great Britain, the Netherlands, and Finland (Hölker et al., 2010;Fox, 2013;MacGregor et al., 2015). ...
... Tragically, nocturnal moth populations have declined by an overwhelming two-thirds since the early 1970s (Fox et al., 2013). In addition to climate change and habitat degradation, the available evidence strongly suggests that ALAN may be driving population decreases in Great Britain, the Netherlands, and Finland (Hölker et al., 2010;Fox, 2013;MacGregor et al., 2015). Like other nocturnal animals, ALAN affects moth populations along a few dimensions. ...
... One group of organisms that are well known for their response to artificial lights is moths, and ALAN has been suggested as one of the potential causes for declines in their species richness and abundance [6,[45][46][47]. Moth species and families vary in their degree of attraction to light [48,49]. ...
... Furthermore, when considered with our prior research on the negative effects of streetlights on larval performance, it becomes clear that streetlights may act as an ecological trap and are probably deleterious to moth populations. The attraction of moths to highly lit areas, paired with the decrease in moth abundances and richness from increased sky glow, may play an important role in observed declines in worldwide moth diversity [45,46]. ...
Ecological studies investigating the effects of artificial light at night (ALAN) have primarily focused on single or a few species, and seldom on community-level dynamics. As ALAN is a potential cause of insect and biodiversity declines, community-level perspectives are essential. We empirically tested the hypothesis that moth species differentially respond to ALAN and that these responses can cause shifts in community composition. We sampled moths from prairie fragments in Colorado, USA. We tested whether local light sources, sky glow, site area and/or vegetation affected moth community diversity. We found that increased sky glow decreased moth abundance and species richness and shifted community composition. Increased sky glow shifted moth community composition when light and bait traps were combined; notably this result appears to be driven entirely by moths sampled at bait traps, which is an unbiased sampling technique. Our results show that ALAN has significant effects on moth communities and that local light sources have contrasting effects on moth community composition compared to sky glow. It is imperative that we better understand the contrasting effects of types of ALAN to comprehend the overall impacts of light pollution on biodiversity declines.
This article is part of the theme issue ‘Light pollution in complex ecological systems’.
... To comprehensively understand temporal insect abundance change, there is a need to identify key environmental variables affecting short-term abundance fluctuations and long-term abundance trends. Environmental drivers that are commonly associated with global insect collapse include habitat destruction, climate change, agricultural intensification (including pesticide use), and invasive species (Fox, 2013;Thomas, 2016;Wagner, 2020;Wepprich et al., 2019). ...
... While our study shows that the biomass of moth functional groups-as defined by key ecological and life-history traits-are either stable or increasing in Finland, most previous studies of moth communities in other areas have reported long-term declines (Fox, 2013;Franzén & Johannesson, 2007;Groenendijk & Ellis, 2011;Valtonen et al., 2017). Comparing our results to the earlier reports from Finland Kohonen, 2020) provides some insights into the importance and effect of temporal resolutions of time series in detecting abundance and biomass trends. ...
Dramatic insect declines, and their consequences for ecosystems globally, have received considerable attention recently. Yet, it is still poorly known if ecological and life‐history traits can explain declines and whether insect decline occurs also at high latitudes. Insects' diversity and abundance are dramatically lower at high latitudes compared to the tropics, and insects might benefit from climate warming in high‐latitude environments.
We adopted a trait‐ and biomass‐based approach to estimate temporal change between 1993 and 2019 in Finnish macro‐moth communities by using data from 85 long‐running light traps. We analysed spatio‐temporal variation in biomass of moth functional groups with Joint Dynamic Species Distribution Models while accounting for environmental variables.
We did not detect any declining trends in total moth biomass of moth functional groups, and most groups were stable over time. Moreover, biomass increased for species using coniferous trees, lichens, or mushrooms as hosts, multivoltine species, as well as monophagous and oligophagous species feeding on trees. We found that length and temperature of the growing season, winter climatic conditions, and habitat structure all partially explained variation in moth biomass.
Although boreal moth communities are rapidly changing due to species turnover, in terms of total biomass they seem to contradict the trend of dramatic insect declines observed globally. This may lessen the immediate possibility of negative bottom‐up trophic cascades in boreal food webs.
... Insect diversity has experienced one of the sharpest declines of all animal groups in recent decades (Dirzo et al. 2014;Hallmann et al. 2017Hallmann et al. , 2021Harvey et al. 2020;Wagner et al. 2021), with habitat specialist species being particularly vulnerable due to their requirements in terms of habitat conditions and food supply (Eskildsen et al. 2015). This also applies to Lepidoptera and among them butterflies in particular due to their often high degree of specialisation (Thomas et al. 2004;Fox 2013;van Strien et al. 2019;Warren et al. 2021). ...
The rock grayling (Hipparchia alcyone) is one of the many butterfly species that has experienced a dramatic decline throughout Central Europe, but no empirical studies exist. This study provides information for conservation measures that protect the entire habitat of the open forests. We compared structures of currently with formerly colonised habitats. Therefore, we carried out vegetation assessments in the larval habitats in order to characterise these areas and derive changes in the habitat structures. The analyses revealed strong structural and qualitative differences between current and former habitats. Succession processes in the once highly unproductive habitats have led to far-reaching changes in environmental conditions. In particular, light supply and the abundance of the caterpillar food plant Festuca ovina are influenced by these changes. In this context, the encroachment of the neophytic Prunus serotina seems to be particularly problematic. In addition, a nectar source dependence on Thymus serpyllum, which is largely absent in the currently not colonised habitats, has to be assumed. The combination of these changes appears to have a negative impact on the butterfly’s populations.
Implications for insect conservation
To conserve H. alcyone in Central Europe, open forest structures must be preserved. Pine forests are no longer utilised continuously as in the past, which accelerates succession processes. In order to safeguard species in open forests, a balance must therefore be found between the endeavours of conventional forest conversion and the promotion of open forests. In addition, it is important to promote the supply of flowers, especially through the establishment of T. serpyllum. Overall, H. alcyone is assumed as an umbrella species for the habitat of open pine forests, and other species would also benefit from the mentioned measures.
... Similar trends were observed in other parts of the world including the tropics (Janzen and Hallwachs, 2019), and a quantitative review demonstrated that insect decline indeed is pervasive in terrestrial insect communities (van Klink et al., 2020). Since then, the body of literature has increased tremendously, yet attribution of trends to certain drivers remains challenging (Fox, 2013;Sánchez-Bayo and Wyckhuys, 2019). Potential drivers range from novel diseases (Vilcinskas, 2019), to light pollution (e.g. ...
Insect decline has been documented in an increasing number of studies, but attribution to potential drivers remains challenging. Climate change poses threats to insect biodiversity, and there is still little data on how climate change is already affecting insect communities. We present a resampling study on long-term trends in leafhopper and planthopper communities of dry grassland reserves in Germany, comparing samples from three sampling decades: 1960s, 2000s and 2010s. Diversity and abundance data were related to weather data and to information on conservation management. Insect communities changed significantly with respect to decade, season and seasonal precipitation but not with respect to mean seasonal temperature. Conservation management had limited effect. Specifically, wetter conditions resulted in significantly higher abundance and richness of insect communities. We infer that apparent decline of water availability in dry grasslands-among other drivers on landscape-level-plays a significant role in shaping communities of phytophagous insects in Central European cultural landscapes. Conservation management has to be adjusted to this development.
... This nescale data complements GBIF ndings by highlighting regional biodiversity hotspots and revealing lesser-known families that are critical for understanding ecological processes and prioritizing conservation(Farashi and Shariati 2017;Wagner et al. 2021). Such granular data are essential for identifying habitats with high conservation value, particularly as many specialist Lepidoptera families remain vulnerable to habitat fragmentation and climate variability(Fox 2013;Hill et al. 2021).Together, GBIF and the catalogue datasets serve as valuable tools for assessing Lepidoptera biodiversity, despite their respective limitations. While GBIF provides a broad-scale, long-term perspective essential for identifying overarching trends, its reliance on opportunistic and unevenly distributed records can result in gaps, particularly in under-sampled or extreme environments like deserts (Montgomery et al. 2021; Rocha-Ortega et al. 2021). ...
This study examined the impacts of climate change on Lepidoptera biodiversity across Iran’s ecoregions using Global Biodiversity Information Facility (GBIF), observational records, and long-term climate data from 1993 to 2022. Biodiversity metrics were analyzed, and Generalized Linear Model (GLM) analysis were used to identify key climatic and ecological drivers of family richness. Spatial analysis revealed a mean family richness of 5.89 (SD=7.13) and a mean Shannon-Wiener Index of 0.83 (SD=0.93) across ecoregions. Biodiversity hotspots, such as the Caspian Hyrcanian mixed forests, Zagros Mountains forest steppe, and Elburz Range forest steppe, exhibited consistently high family richness (19, 17, and 16 families, respectively) and balanced family compositions. In contrast, arid ecoregions, including the Registan-North Pakistan sandy desert and Baluchistan xeric woodlands suffered from insufficient sampling, limiting biodiversity assessments. Temporal analyses revealed forested regions had relatively complete accumulation curves while arid and semi-arid regions displayed uneven and incomplete sampling. Comparative analyses demonstrated that GBIF documented 27 unique families out of 70 families in observational records. Negative Binomial GLM showed that temperature positively influenced family richness, while higher precipitation negatively impacted family-level distribution. Comparative analysis between GBIF data and observational records revealed complementary strengths. GBIF provided broad-scale trends, while localized surveys uncovered specialist families often overlooked in global datasets. These findings emphasize the need to prioritize conservation efforts in biodiversity-rich ecoregions and addressing sampling gaps in underrepresented areas to mitigate climate change impacts on Lepidoptera in Iran.
... Dietary plasticity can be important to this critically endangered bird [32], as it means that the species has certain ability to cope with unusual challenges such as food shortages [94]. However, arthropods are experiencing global declines in diversity and abundance in recent decades [95,96], mostly due to habitat loss and degradation, and to agricultural intensification (pesticide usage, increased use of fertilizers and frequency of agronomic measures [97,98]). The loss of arthropod biomass is expected to provoke cascading effects on food webs [95], raising concern about food limitations that could adversely affect the viability of insectivorous birds [99]. ...
A species’ diet is highly dependent on the availability of food resources in space and time, as well as on intrinsic factors such as sex or age. Accurate assessments of variations in the diet composition of bird populations across spatial scales, seasons and demographic groups are essential not only for understanding the basic ecology of species, but also for the conservation of endangered ones. However, our current knowledge about how birds’ diet change according to spatio-temporal variations or intrinsic factors is very limited. Here, we used a multi-marker metabarcoding approach to characterize the diet of a declining shrub-steppe passerine, the Dupont’s Lark (Chersophilus duponti), throughout a large part of its global distribution range. We also investigated spatial, phenological and sexual variations in its diet. Using markers from two genomic regions (18S and COI), we analyzed fecal samples from 303 adult Dupont’s larks from Morocco and Spain during the breeding and non-breeding seasons. Overall, arthropods from the orders Coleoptera, Lepidoptera, Julida and Orthoptera were the main prey consumed by Dupont’s Larks. We found that Dupont’s Lark diet varied spatially, as well as temporally, reflecting dietary plasticity in response to changes in prey availability across landscapes and the species’ phenological periods. High dietary overlap and no differences between sexes were observed, suggesting similar foraging behavior and nutritional requirements in both sexes. This is the first study providing detailed information on Dupont’s Lark food ecology over much of its distribution, which is fundamental for the management and conservation of this declining steppe species.
... After a moth was captured, it was kept in the dark and transported to the release site. Between capture and release of a moth there was a minimum acclimation time of 40 min (usually more than 60 min), and we assume that animals were dark-adapted at the time of take-off since the return to full ocular sensitivity takes around 30 min in moths (9). When the animals were kept for longer times, they were fed with sugar solution (2 M) to ensure that they had enough energy to perform a flight (except for E. potatoria that do not assimilate food as adults). ...
One of the most dramatic changes occurring on our planet is the ever-increasing extensive use of artificial light at night, which drastically altered the environment to which nocturnal animals are adapted. Such light pollution has been identified as a driver in the dramatic insect decline of the past years. One nocturnal species group experiencing marked declines are moths, which play a key role in food webs and ecosystem services such as plant pollination. Moths can be easily monitored within the illuminated area of a streetlight, where they typically exhibit disoriented behavior. Yet, little is known about their behavior beyond the illuminated area. Harmonic radar tracking enabled us to close this knowledge gap. We found a significant change in flight behavior beyond the illuminated area of a streetlight. A detailed analysis of the recorded trajectories revealed a barrier effect of streetlights on lappet moths whenever the moon was not available as a natural celestial cue. Furthermore, streetlights increased the tortuosity of flights for both hawk moths and lappet moths. Surprisingly, we had to reject our fundamental hypothesis that most individuals would fly toward a streetlight. Instead, this was true for only 4% of the tested individuals, indicating that the impact of light pollution might be more severe than assumed to date. Our results provide experimental evidence for the fragmentation of landscapes by streetlights and demonstrate that light pollution affects movement patterns of moths beyond what was previously assumed, potentially affecting their reproductive success and hampering a vital ecosystem service.
... Agricultural intensification and urbanization, by replacing traditional low-intensity agriculture and natural areas, have led to a dramatic reduction in both local and regional diversity [3]. A severe effect of land use changes on insects and the ecosystem services they provide has been reported in disparate insect orders such as Coleoptera [5], Diptera [6], and Lepidoptera [7]. Furthermore, land use intensification is a major driver of biotic homogenization and can favor generalist insects at the expense of specialists that feed on a limited range of food sources [8]. ...
In alpine environments, open habitats alternate with wood to create a habitat mosaic that shapes insect community composition and diversity. Dung beetles are an important group of insects specialized in feeding on vertebrate dung whose availability also depends on habitat type. Although the habitat preferences of dung beetles have been extensively studied, few studies have addressed the influence of habitat structure and temperature on dung beetle communities in alpine environments. We sampled dung beetles in pastures, at the edges between pasture and wood, in inner and outer woods of two alpine areas at different altitudes (two sites per area). We found that pastures had higher mean temperatures compared to other habitat types and hosted the highest number of species. However, the interaction between habitat and altitude significantly affected species richness and abundance, suggesting that habitat type and temperature modulate the response of dung beetles in the study area. Edges hosted intermediate communities between pastures and woodlands and were populated by both pasture and woodland specialists. Our results suggest that maintaining pastures is crucial to preserving dung beetle communities.
... lack of European Red List of moths), a large amount of common and widespread macro-moth species has recently declined in some European countries (Conrad et al. 2006;Groenendijk and Ellis 2011). This might be linked to habitat shrub encroachment, agricultural intensification, changing forest management and climate change (Fox 2013). Some common species have already experienced enlarging their geographic (latitude and longitude) and altitudinal distribution and/or increasing their generation numbers. ...
Insects and plants share a close relationship; plants provide feeding opportunities, ecological niches, and shelters for insects, while insects, in turn, facilitate pollination for plants. Management actions might positively or negatively affect insect species richness and/or abundance, in particular, forest practices can significantly influence insect communities. In this study, we investigated the effects on plant and moth communities following the realization of an ecological corridor (composed of 10 clearings) in forest in NW of Italy. Specifically, through plant surveys and moth light traps, we investigated plant and moth communities and their relationship in newly shaped clearings and their surrounding forest. We found that plants responded quickly to clearing formation, presenting differentiated plant communities between xero-thermophile clearings, mesophile clearings and forest. These differences reflected on moth communities as well, allowing to find indicator species for each ecosystem. Structural variables (i.e. openness) and topography (i.e. elevation) were key factors affecting the differentiation of moth communities. On the other hand, plants explained most of the variance in moth communities, so, through plants, we differentiated moth communities into those typical of xero-thermophile clearings, mesophile clearings and forest. In conclusion, forest management significantly affects plant and moth communities. Newly shaped clearings support higher species richness (including specialist species) and abundance than closed canopy forest. To increase species richness and abundance for both plants and moths, we suggest conservation measures that include creating open habitats within forests at medium elevation (650–950 m a.s.l.).
... However, amid the ongoing global decline of insects (Wagner et al., 2021), populations of many insect pollinators, such as bees (Cameron & Sadd, 2020), butterflies and moths (Fox, 2013), have plummeted in recent decades. These declines highlight the interconnected nature of plant and pollinator conservation. ...
Many nature‐based solutions (NBS), including urban greenspaces, urban agriculture and agroforestry, depend upon animal‐pollinated plants to sequester carbon or to provide other ecosystem services. Thus, long‐term success of these solutions also depends upon resilient pollinator communities.
Despite their importance to functioning communities, a literature search revealed that 0%–3% of papers on NBS and related topics considered pollinators or pollination. Pollinators were more likely to be considered in the subgroup of papers on NBS related to agricultural production, where 12.5% considered pollination.
Conservation of species interactions is essential to conservation of biodiversity and the sustained benefits of NBS. By applying our understanding of the ecology of plant‐pollinator mutualisms to the implementation of NBS, we can promote their functioning under future climatic conditions. In particular, we point to the need to identify keystone plants and pollinators, those species that contribute most to biodiversity maintenance, community stability and ecosystem function, and to leverage these species and their interactions in NBS and conservation efforts. We further advocate for the use of phylogenetic trait‐based analyses to understand the characteristics associated with keystoneness.
Synthesis: Resilience of pollination services rests upon the responses of keystone species and their partners, and the likelihood that they continue to express traits that confer mutual benefit under future climates. By understanding the traits of species of outsized importance to their communities, we gain insight into the mechanisms underlying the resilience of pollination services and the NBS that rely on those services in a changing world.
... Artificial light desynchronizes their activities such as mating, egg laying (Owens and Lewis, 2018), leading to incomplete life cycle thereby reducing the insect population. Soil pollution due to the addition of fertilizers result in soil acidification and eutrophic conditions that are detrimental to the growth and survival of insects (Fox, 2013). Increased use of fertilizers has led to increase in aphid population (kyto et al., 1996) while negatively impacting most insects, thereby, leading to dysfunctional ecosystems. ...
Trichoptera is one of the most diverse orders of aquatic insects and important water quality indicators, due to their presence in almost all segments of freshwater ecosystems. Caddisflies of Europe and adjacent areas are represented by 132 genera and 1855 species up to date. The most species rich genera in Europe are Drusus, Rhyacophila, Hydropsyche and Tinodes, each with more than 100 species, constituting thus slightly more than 50% of the total caddisfly species. Europe and adjacent areas have a high number of endemic species, mostly belonging to the families Limnephilidae, Beraeidae, Glossosomatidae, Hydroptilidae, Philopotamidae, Psychomyiidae and Rhyacophilidae.
Despite their importance and routine usage in biomonitoring, caddisflies are still not given proper conservation importance. International Union for Conservation of Nature (IUCN) still does not have on European or global level a list of assessed caddisfly species. However, on a regional scale, several national and regional Red Lists of caddisflies exist, or there are lists of caddisfly species included in national or regional Red Lists or Books of Fauna. While in most of the European countries which are part of European Union, threatening activities in freshwater ecosystems affecting caddisflies are addressed seriously, legally and practically, in Southeastern European countries there is no major action towards the prevention of these activities, or restoration of damages caused by their long impact.
... While it is evident that life history traits play an important part in species' response to climate change, the relative importance of different traits in determining species' responses is still unclear. Many studies have sought to find traits that can predict species response to climate change, but this may not be possible due to the variety of both species and the anthropogenic forces that may impact them (Fox 2013;Wagner et al. 2021;Tordoff et al. 2022). Nevertheless, trait-based studies such as Tordoff et al. (2022) have linked various life history traits to distribution and abundance trends of British moths. ...
Climate change has led to changes in the phenology of Lepidoptera species. While phenological shifts have been previously measured for moth species in England and Wales, the drivers of these shifts are not well known. Here, we use data from the National Moth Recording Scheme and the Garden Moth Scheme to investigate the drivers of phenology in 149 moth species over a 50 year period from 1970 to 2019. We investigate whether there have been phenological shifts in adult emergence using three phenology metrics: First Emergence (FE), Peak Emergence (PE), and Emergence Standard Deviation (ESD) in relation to life history traits and temperature. Overwintering stage had a significant impact on moth phenology, so we analysed species that spend the winter as eggs, larvae or pupae separately. Overall phenological changes were different depending on overwintering stage category and phenological measure, with the rate of phenological shifts increasing with later overwintering life stages in response to both temperature and year. The overwintering stage larva was the only one impacted by diet, with those that feed on woody hostplants emerging ~ 17 days later than species with herbaceous hostplants. These results indicate that species that either overwinter in earlier life stages or have woody hostplants may be less adaptable to climate change, and thus should be the targets of conservation efforts.
... Ñòàí ¿õí³õ ïîïóëÿö³é â ïåâí³ ïåð³îäè ìîaeíà îõàðàêòåðèçóâàòè ÿê äåïðåñèâíèé, àëå â ³íø³ -ñïîñòåð³ãàºòüñÿ ð³çêå çðîñòàííÿ ÷èñåëüíîñò³ [1,2]. Äåÿ-ê³ âèäè øê³äíèê³â ïîâí³ñòþ âòðà-÷àþòü ñâîþ àêòóàëüí³ñòü, ïðîòå ¿ì íà çì³íó ç'ÿâëÿþòüñÿ ³íø³ [3][4][5]. Äîñèòü ÷àñòî òàê³ ð³çê³ çá³ëüøåííÿ ÷èñåëüíîñò³ ô³òîôàã³â, òàê çâàí³ «ñïàëàõè», âñå ùå ëèøàþòüñÿ äëÿ àãðàð³¿â âàaeêî ïåðåäáà÷óâàíèìè [6][7][8][9]. Çàçíà÷åí³ âèùå êîëèâàííÿ ÷èñåëüíîñò³ ó ïîïóëÿö³ÿõ ð³çíèõ âèä³â òâàðèí, à îñîáëèâî êîìàõ, íàñàìïåðåä çóìîâëåí³ âïëèâîì àíòðîï³÷íèõ òà åêîëîã³÷íèõ ÷èí-íèê³â ð³çíî¿ ïðèðîäè, ñåðåä ÿêèõ ïîãîäí³ ³ êë³ìàòè÷í³ çì³íè çàéìàþòü íå îñòàííº ì³ñöå [10][11][12][13][14]. ...
Goal. Create a forecast of the development of harmful organisms in cereal crops, to determine the economic feasibility of applying plant protection measures. Methods. Analysis of the phytosanitary state of cereal crops in Ukraine, where the main attention is paid to the dominant pest species. Analysis of the areas of distribution of these pests, population dynamics, their phenology and the state of populations in the context of natural and climatic zones (Steppe, Forest-steppe and Polissya). To assess the phytosanitary state of crops, and its dynamic changes, the following are used: — the results of phytosanitary monitoring of crops (according to generally accepted methods), which were carried out directly by the staff of the forecast laboratory of the Institute of Plant Protection of NAAS; — current reports of researchers from other laboratories of the Institute of Plant Protection of NAAS from the places of business trips; — materials of decadal reports of regional plant protection stations, as well as signaling and forecasting points; — information on the phytosanitary situation from regional state research stations and institutes of NAAS. Results. A study of the phytosanitary state of cereal crops on the territory of Ukraine was carried out, the dominant species of pests were identified, materials were prepared regarding the peculiarities of the phytosanitary state in the conditions of the year, and a long-term (annual) forecast of the development of pests for the next year was drawn up, based on the appropriate analysis of the data obtained. Conclusions. In recent years, climate change in Ukraine has manifested itself through an increase in the average annual temperature, and an increase in the sum of effective temperatures. A decrease in the zone of sufficient soil moisture was noted, its line shifted to the north. Under the influence of abiotic factors, pests constantly change the boundaries of their habitat and zones of damage, therefore reliable protection of crops is impossible without constant monitoring, constant clarification of the species composition of phytophages, and phytosanitary forecast. Improved methodological approaches for assessing the phytosanitary state of acrocyanoses and the promptness of obtaining relevant data will allow agricultural producers to make timely decisions on the economic feasibility of using certain plant protection products.
... According to these assignments, the by far most important threat to individual species is land use change in a broad sense, encompassing diverse phenomena such as deforestation, commercial afforestation, agricultural intensification, abandonment of traditional agricultural practices, and urbanization (van Swaay et al., 2010;Filz et al., 2013;Börschig et al., 2013). At a local to landscape scale, the extensive amount of fertilizers and pesticides applied in agriculture is generally acknowledged to play an additional important role (Tilman et al., 2001;Benton et al., 2002;Fox, 2013). ...
Land use change, as a result of many local-scale decisions scaling up to large spatial extents, is considered the main threat to European butterflies. The impact of large-scale pressures, such as atmospheric nitrogen deposition or climate change, is less understood or less documented, respectively. However, it is acknowledged that they might reinforce the pressure on already threatened species. To evaluate the additional threat exerted by these pressures we compared their geographical pattern to those of threatened butterflies across Europe. We therefore derived range maps of 383 butterfly species and used two species-specific threat assessments derived from national and European Red Lists. We then used Spearman rank-correlations and beta-regressions to compare two metrics of species threat per 10 × 10 km raster cells with geographical patterns of cumulative nitrogen de-positions from 1980 to 2015, as well as the magnitude of change in precipitation sums and temperature means between the decades 1979-1988 and 2004-2013. We found that threatened species tend to concentrate in areas with high nitrogen depositions and pronounced summer temperature changes. In particular, parts of central and eastern Europe were both hotspots of threatened butterflies and hotspots of climatic pressure. This spatial coincidence of the distribution of threatened butterfly species with large-scale patterns of nitrogen depositions and recent climate warming indicates an already considerable risk of regional to continental extinctions that will likely increase further in the future as climate change will most likely intensify. Consequences for area-based conservation measures are discussed.
... Furthermore, Lepidopterans are valuable indicators of environmental quality, considering their high degree of host-plant specialization and vulnerability to habitat deterioration (Erhardt and Thomas 1991). Given their presence in a broad range of habitats, the loss of Lepidoptera may directly influence the provisioning of key ecosystem services, such as pollination and natural pest control (Fox 2013). ...
... Insects experience stressors from many directions (Wagner et al. 2021), be it the fragmentation, degradation, and destruction of habitats (Fabienne Harris and 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.
... Understanding the behavior and dietary preferences of these moths is essential, not just because of their pollination role, but also due to their potential as agricultural pests. For instance, while adult nocturnal moths feed primarily on nectar and pollen, their larvae exhibit herbivorous tendencies, causing damage to host plants [13]. Gaining knowledge about these plants is pivotal for effective pest management. ...
Nocturnal moths (Lepidoptera) are important pollinators of a wide range of plant species. Understanding the foraging preferences of these insects is essential for their scientific management. However, this information is lacking for most moth species. The present study was therefore conducted to delineate the host plant feeding and pollination ranges of an agriculturally important nocturnal moth species Athetis lepigone by identifying the pollen species adhering to their bodies during long-distance migration. Pollen grains were dislodged from 1871 A. lepigone migrants captured on Beihuang Island in the Bohai Strait between 2020 and 2021. This region is a key seasonal migration pathway for A. lepigone in northern China. Almost 20% of all moths sampled harbored pollens, providing direct evidences that this moth species may serve as pollinators. Moreover, at least 39 pollen taxa spanning 21 plant families and 31 genera were identified, with a preference for Asteraceae, Amaranthaceae, and Pinaceae. Additionally, the pollen adherence ratios and taxa varied with moth sex, inter-annual changes, and seasonal fluctuations. Most importantly, the pollen taxa were correlated with insect migration stages and indicated that A. lepigone bidirectionally migrates between central China (Shandong, Hebei, and Henan Provinces) and northeastern China (Liaoning Province). Overall, the findings of the present work provide valuable information on the pollination behavior, geographical origins, and pollination regions of A. lepigone moths and could facilitate the design and optimization of efficacious local and regional management strategies for this important insect.
... The order Lepidoptera, commonly known as moths and butterflies, offers key insights into ecosystem health and resilience [6]. Studying how changes in the distribution, diversity, and abundance of moths are influenced by environmental changes and disturbances and how the responses are modified by species traits can yield significant insights into how biodiversity will respond to human activities in the future [7,8]. Current environmental changes impose intense pressure on species, especially those with narrow and specific ecological requirements, leading to decreased population sizes, shrinking distribution ranges, and increased extinction rates [9][10][11]. ...
Simple Summary
This research investigates moth biodiversity in two southern Swedish provinces, Västergötland and Småland, spanning from 1974 to 2019. The moth diversity over these years was evaluated using data collected from literary sources. To augment this dataset, a light trap was installed in each province in 2020. The data demonstrate enhanced diversity in Kalmar, Småland, and a more rapid colonisation rate throughout the study period in Småland compared to Västergötland. Noteworthily, our traps in Västergötland and Småland captured 44% and 28% of the known moth species in these provinces, respectively. We reveal significant associations between the probability of species presence in the traps and specific traits when contrasted with a provincial species pool. Traits disproportionately represented in the traps encompass species with considerable variation in colour patterns, generalist habitat and host plant preferences, extended flight periods, and species that primarily overwinter as eggs. This research underscores the influences of climate change and human activities on the shaping of moth biodiversity.
Abstract
As moths are vital components of ecosystems and serve as important bioindicators, understanding the dynamics of their communities and the factors influencing these dynamics, such as anthropogenic impacts, is crucial to understand the ecological processes. Our study focuses on two provinces in southern Sweden, Västergötland and Småland, where we used province records from 1974 to 2019 in combination with light traps (in 2020) to record the presence and abundance of moth species, subsequently assessing species traits to determine potential associations with their presence in anthropogenically modified landscapes. This study design provides a unique opportunity to assess temporal changes in moth communities and their responses to shifts in environmental conditions, including anthropogenic impacts. Across the Västergötland and Småland provinces in Sweden, we recorded 776 moth taxa belonging to fourteen different taxonomic families of mainly Macroheterocera. We captured 44% and 28% of the total moth species known from these provinces in our traps in Borås (Västergötland) and Kalmar (Småland), respectively. In 2020, the species richness and abundance were higher in Borås than in Kalmar, while the Shannon and Simpson diversity indices revealed a higher species diversity in Kalmar. Between 1974 and 2019, the colonisation rates of the provinces increased faster in Småland. Ninety-three species were found to have colonised these provinces since 1974, showing that species richness increased over the study period. We reveal significant associations between the probability of a species being present in the traps and distinct traits compared to a provincial species pool. Traits over-represented in the traps included species with a high variation in colour patterns, generalist habitat preferences, extended flight periods, lower host plant specificity, and overwintering primarily as eggs. Our findings underscore the ongoing ecological filtering that favours certain species-specific traits. This study sheds light on the roles of climate change and anthropogenic impacts in shaping moth biodiversity, offers key insights into the ecological processes involved, and can guide future conservation efforts.
... Russian biologists rarely conduct such studies on the example of insects [1][2][3]. At the same time, Lepidoptera is a recognized model group being an important indicator in assessing the environmental conditions of the territory [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. ...
This paper aimed to compare the diversity and abundance of fauna of Lepidoptera on wetland sites damaged by peat extraction and remained in their natural state, which locate on the territory of the Ramsar wetland in the Nizhny Novgorod region. The surveys were curried out monthly in May–September 2021. We used methods of attracting moths to a white screen using mercury and ultraviolet lamps (5 nights per each study plot). Diurnal butterflies were being identified along pedestrian routes (total length – 11.4 km) during a day. Indices characterizing the α- and β-diversity of Lepidoptera were calculated. At both plots, we revealed the species diversity of Macrolepidoptera more than 70%. According to our results the abundance and diversity of Macrolepidoptera in the study plots seem to be the same. In the course of succession, after the complete destruction of peat bogs and forests on a site surrounded by intact communities, species abundance and diversity is rapidly restored and reaches a high level. The composition of faunas in the transformed and undisturbed plots differs significantly; the similarity in Jacquard is 44.7%. The ecological features of butterfly species recorded only on one of the study plots were evaluated. The role of the surveyed territories as habitats of rare and endangered butterfly species is shown as well.
... Many studies describe falling populations either regionally or more locally for a diverse range of taxa: birds in the UK [13], bees [14], moths [15], farmland invertebrates [16], reptiles [17], amphibians [18], and predatory fish [19]. This may arise from a simple mechanism such as overharvesting or a complex suite of factors. ...
Loss of habitat can take many forms, ranging from the fragmentation of once-continuous habitat to the slow erosion of populations across continents. Usually, the harm leading to biodiversity loss is not immediately obvious: there is an extinction debt. Most modelling research of extinction debt has focussed on relatively rapid losses of habitat with species loss happening in response afterwards. In this paper, using a niche-orientated community model we compare and contrast two different mechanisms and find contrasting patterns of extinction debt. From small fragments, we typically see the rapid initial loss of many species, followed by a slower loss of species on larger timescales. When we consider slow incremental declines of population sizes, we find initially a slow rate of extinction which subsequently increases exponentially. In such cases, the delayed extinctions may go undetected initially both because the extinctions may be small relative to background randomness and because rate itself is not constant and takes time to reach its maximum.
In recent decades, the use of pesticides has become fundamental to agricultural growth. However, the persistent and toxic nature of pesticides has led to significant concerns regarding their ecological and human health consequences. Therefore, for a better understanding of pesticide contamination and its potential risks, here we assessed the levels of five emerging pesticides—acetochlor, imidacloprid, MCPA, atrazine, and allethrin—in soil samples from ponds used for irrigation and in drinking water samples from nearby areas in Lahore, Pakistan. Our findings revealed that 100% of the samples were contaminated, posing substantial ecological and human health risks. Based on the toxic units (TUsum), all the soil samples showed higher toxic pressure, exceeding acute and chronic toxicity thresholds for earthworms, while 100% of water samples posed chronic toxicity risks to crustaceans and 10% to algae. Pollution index (PI) analysis further classified 100% of the soil samples and 10% of the water samples as highly polluted. These findings show high-pesticide residues in both soil and water and highlight immediate risk assessment and mitigation measures to protect non-target organisms. This preliminary information can be used to adopt risk assessment monitoring programmes and help higher authorities in making policies and guidelines to mitigate the escalating risk for ecology and humans.
In 2023 the wind industry hit a milestone of one terawatt of installed capacity globally. That amount is expected to double within the next decade as billions of dollars are invested in new wind projects annually. Wildlife mortality is a primary concern regarding the proliferation of wind power, and many studies have investigated bird and bat interactions. Little is known about the interactions between wind turbines and insects, despite these animals composing far more biomass than vertebrates. Turbine placement, coloration, shape, heat output, and lighting may attract insects to turbines. Insects attract insectivorous animals, which may be killed by the turbines. Compiling current knowledge about these interactions and identifying gaps in knowledge is critical as wind power grows rapidly. We reviewed the state of the literature investigating insects and wind energy facilities, and evaluated hypotheses regarding insect attraction to turbines. We found evidence of insect attraction due to turbine location, paint color, shape, and temperature output. We provide empirical data on insect abundance and richness near turbines and introduce a risk assessment tool for comparing wind development with suitable climate for insects of concern. This understudied topic merits further investigation as insects decline globally. Compiling information will provide a resource for mitigation and management strategies, and will inform conservation agencies on what insects may be most vulnerable to the expansion of wind technologies.
Debate continues over the extent of insect declines and losses of species, but with general acceptance that these are real, substantial, and a major concern for ecological function of the natural world. Recent claims of very severe and continuing losses aroused much attention and concern, but the evidence is sometimes difficult to evaluate, with long-term trends from ‘popular’ insects (notably some Lepidoptera and Coleoptera) the most informative. Much uncertainty persists, and a central task in promoting insect conservation is to convey that uncertainty and accompanying concern to conservation managers. Lack of proven detail does not equate to lack of significance, and conservation must proceed in the absence of exact details of local or more widespread declines, with recognition that those declines to a large extent reflect human activities.
The major—and most obvious—drivers of insect decline flow from anthropogenic activities whereby the condition of most terrestrial and inland water ecosystems is changed. Loss and degradation of habitats is the universal over-riding concern, with major land transformations from urbanisation, agricultural conversion, and forestry. Additional threats are associated with pollution, invasive species, and exploitation. All are difficult to evaluate and all are also overlain by the impacts of continuing climate change. Understanding these interacting drivers and preventing or countering their impacts is a key theme in insect conservation. This chapter briefly introduces the variety of threats to insect life, and how they may be considered in practical conservation.
Despite high-quality insect food being often restricted in cities, insects are important for the development of birds. Nonetheless, plenty of insects are smashed on cars, and they are available for those species that are able to use them. We used both our own data and community science and Internet sources for surveying global, national, and local data about birds using insects on cars. Our results contained a total of 308 observations of birds collecting insects on car panels, which indicated that 39 species used this food resource since 1928 in 33 countries. Most observations considered the House Sparrow, followed by the White Wagtail and several species of corvids. European urban bird species observed to use insects on cars had a larger residual brain size. There was also some indication that bird species using insects on cars had a larger number of innovations (i.e., production of novel behaviors), greater diet generalism, and longer times living in urbanized areas than birds not observed using insects on cars. Often these species are also resident and able to use food offered in feeding sites. We assume that more bird species will use insects on cars in the future, as urban insect populations continue to decline, and thereby insects on cars will increasingly become more important sources of food for urban birds.
Journal of Natural Resource And Development published January to June 2024
Journal of Natural Resource And Development published full journal January to June 2024
Pollinators play important roles in providing pollination services, maintaining biodiversity, and boosting crop production. Even though pollinators are essential to the environment and agriculture, their decline has been noted across multiple studies in the recent past. Both natural and anthropogenic factors have contributed to their decline. Much of the focus has been placed on climate change, habitat loss, pests and pathogens, and synthetic pesticides, but relatively little is known about the effects of biopesticides. Biopesticides are biological control agents derived from living organisms and are classified into three groups: microbial, biochemical, and plant-incorporated protectant-based products. Biopesticides are formulated similarly to their synthetic counterparts and are readily available and used within urban and agricultural settings by pest management experts and household residents. The general public and much scientific literature support the prevailing idea that biopesticides are environmentally safe and pollinator friendly in comparison with synthetic versions. However, such generalizations are based on studies with a few key pollinator species and may not be relevant to several other species that provide crop pollination services. Studies focused on native pollinators have shown that some biopesticides have lethal and sublethal effects. Because each biopesticide exhibits varying effects across pollinator species, it could be dangerous to generalize their non-toxicity across taxa and environmental settings. In this article, recent research in this direction is discussed.
One approach for measuring the potential biodiversity in new urban construction projects is through ecological models that predict how wildlife will respond. For the United Kingdom, such models have only been developed for birds, but to maximise the extent to which models represent overall biodiversity, species from different indicator groups must be considered.
Here, we assess this possibility for butterflies by combining citizen science survey data with high‐resolution digital maps. We derive detailed characteristics of urban landscapes around survey sites using previously established methods and quantify their relationship to counts of adults of 18 butterfly species in urban and peri‐urban settings.
Higher butterfly counts were found when traversing urban sites with larger areas of semi‐natural grassland, other managed greenspaces and adjacent arable land. Most of the butterfly community were found to have negative relationships with highly built‐up or fragmented landscapes.
We found high species‐specificity for different details of urban form, particularly in habitat elements such as gardens, vegetation around railways and grass verges.
Policy implications . Improving biodiversity is now part of legislation governing new construction projects from England and Wales. However, predicting quantitative changes from hypothetical land‐use modifications remains challenging. Our models provide the foundation through which butterfly abundance could be integrated into an urban biodiversity assessment tool, providing species‐ and community‐level statistics to non‐specialists from the urban planning and design sector. This would allow them to hone configurations for built surfaces, private gardens, greenspaces and wildlife areas and assess their capacity to provide residents with the intended access to nature.
During the last decades, a massive bark beetle outbreak has caused Norway spruce (Picea abies) diebacks across Central Europe, including the Czech Republic. This situation is much studied with respect to the dynamics of the pests, operations in forest planting and economic and societal impacts. In stark contrast, studies of biodiversity consequences were largely restricted to mountain protected areas within P. abies’ natural distribution, omitting the situation in planted forests of lower elevations. We surveyed vascular plants, butterflies, moths, and saproxylic beetles in dieback-affected spruce plantations in three representative submontane regions of the Czech Republic. We related the quantitative characteristics of the sampled assemblages, as per their species composition, to forestry interventions (dead, sparse, salvage logged, and replanted stands), the representation of vegetation layers, plant species composition (for the insect taxa), and local dead wood supply. Vascular plants did not respond to forestry interventions, reflecting more likely such circumstances as humidity and soils of the sites. The highest numbers of butterflies preferred clear-felled clearings, which were abundantly occupied by grassland species; butterfly species composition responded to the representation of vegetation layers. The highest numbers of moths were found in dead stands, owing to moths developing on decaying plant tissues or lichens; the assemblages composition responded to the composition of vegetation. The highest diversities of saproxylic beetles were found in sparse stands with retention of some non-spruce trees, but contrary to expectations, they responded only weakly to dead wood supply, probably because dead wood was abundantly present at study plots. The transient habitats created by post-dieback operations were species rich, hosted assemblages unusual for recent Central European landscapes, and contained high representations of red-listed species. The diebacks thus contribute to preserving biodiversity at landscape scales. We understand that the post dieback habitats, and associated assemblages, will eventually succumb to forestry operations. To retain some of the biodiversity benefits in future forest plantations, we recommend retaining at least some amount of open structures and spontaneously developing wetlands. Prolonging terms for afforestation and stabilisation of planted forests or support of non-spruce trees would be also beneficial.
When civil engineering work is performed in a rich natural environment surrounded by forests and streams, there is a strong need to protect the surrounding environment. In particular, when nighttime construction lighting is used, it affects not only the construction area but also a wide surrounding area, so countermeasures are taken by reducing the exposure area and using light sources with low insect attractiveness. An example of a light source with low insect attractiveness is LED lamps, which emit almost no ultraviolet light. On the other hand, some species of insects are known to be attracted even by LED lights in large numbers, and further researches are required to clarify the characteristics of these insects. In this paper, we conducted insect attraction tests using LEDs of various wavelengths and flicking cycles for a wide range of insect species in near a civil engineering sites. In addition, we conducted tests to compare the insect attraction of ordinary white LEDs and LEDs that blink at 100 Hz and have various color temperatures, with the aim of applying these LEDs to actual work sites. The results showed that both wavelength and flicking cycle had different effects on different insect order. In the comparison of wavelengths, the three-color RGB LEDs tended to attract fewer insects to the color containing more red wavelengths in most orders, while single-chip LEDs with the blue LED and yellow phosphor did not attract fewer insects even when the color temperature was lowered, depending on the test site and season. In the comparison of flicking cycle, the total number of insects captured with 5 to 475 Hz decreased as the frequency of flicking decreased, while a comparison of pulsed lighting at 100 Hz and constant current lighting showed an increase in some species with pulsed lighting.
Ecosystem functions and services are severely threatened by unprecedented global loss in biodiversity. To counteract these trends, it is essential to develop systems to monitor changes in biodiversity for planning, evaluating, and implementing conservation and mitigation actions. However, the implementation of monitoring systems suffers from a trade‐off between grain (i.e., the level of detail), extent (i.e., the number of study sites), and temporal repetition. Here, we present an applied and realized networked sensor system for integrated biodiversity monitoring in the Nature 4.0 project as a solution to these challenges, which considers plants and animals not only as targets of investigation, but also as parts of the modular sensor network by carrying sensors. Our networked sensor system consists of three main closely interlinked components with a modular structure: sensors, data transmission, and data storage, which are integrated into pipelines for automated biodiversity monitoring. We present our own real‐world examples of applications, share our experiences in operating them, and provide our collected open data. Our flexible, low‐cost, and open‐source solutions can be applied for monitoring individual and multiple terrestrial plants and animals as well as their interactions. Ultimately, our system can also be applied to area‐wide ecosystem mapping tasks, thereby providing an exemplary cost‐efficient and powerful solution for biodiversity monitoring. Building upon our experiences in the Nature 4.0 project, we identified ten key challenges that need to be addressed to better understand and counteract the ongoing loss of biodiversity using networked sensor systems. To tackle these challenges, interdisciplinary collaboration, additional research, and practical solutions are necessary to enhance the capability and applicability of networked sensor systems for researchers and practitioners, ultimately further helping to ensure the sustainable management of ecosystems and the provision of ecosystem services.
We present a genome assembly from an individual male Laspeyria flexula (the Beautiful Hook-tip; Arthropoda; Insecta; Lepidoptera; Erebidae). The genome sequence is 450.9 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.58 kilobases in length. Gene annotation of this assembly on Ensembl identified 13,281 protein coding genes.
We present a genome assembly from an individual male Hemistola chrysoprasaria (the Small Emerald; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 438.2 megabases in span. Most of the assembly is scaffolded into 30 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.63 kilobases in length. Gene annotation of this assembly on Ensembl identified 17,512 protein coding genes.
The increase in the world population is projected to reach 9.3 billion by the year 2050 and will no doubt require a significant and continued increase in food production to meet the food needs. The adoption of intensive agriculture began in the second half of the twentieth century and is dependent on diverse agrochemicals. Agricultural intensification practices involve the enlargement of small farms into large ventures, the concentration on the culture of single species of exotic cash crops, and the use of pesticides and fertilizers. The results from these practices have been very encouraging in terms of the amount of food produces but not without a price on biodiversity and environmental integrity. For instance, it has constituted a source of threat to wildlife habitats, niche functionality, and ecosystem processes and services all over the world with the outcome depending on the type and amount of agrochemical commonly used in the locale. This chapter attempts to collate evidence from previous studies on the extent of information on the detrimental effects of agricultural intensification through agrochemical use on the various environments and flora and fauna diversity around the world. The harmful effects of these modern agricultural practices are taking a negative toll on diverse important aspects of biodiversity and indirectly affecting human sustenance on Earth. To address this problematic trend, policies such as the adoption of sustainable agricultural practices are crucial. An example of such is organic agriculture which has less hazardous effects on biodiversity. These practices must be put in place by authorities and stakeholders in the agriculture industry so that food can be secured and conservation of biodiversity will be of major interest.KeywordsAgricultural intensificationAgrochemicalsBiodiversityEcosystemWildlife habitatsHabitat loss
We present a genome assembly from an individual female Crocallis elinguaria (the Scalloped Oak; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 430.4 megabases in span. Most of the assembly is scaffolded into 17 chromosomal pseudomolecules, including the Z and W sex chromosomes. The mitochondrial genome has also been assembled and is 16.86 kilobases in length. Gene annotation of this assembly on Ensembl identified 17,741 protein coding genes.
1. Evidence is mounting that migration in ectotherms is more widespread than formerly believed. Thus, a number of insects living in temperate climates, including locusts, butterflies, moths and dragonflies, following seasonal migration strategies show high responsiveness to alterations in climatic processes, similar to a broad taxonomic range of birds. On global scales, migratory insects include iconic large butterflies, dragonflies and also a number of crop pests. However, insect migrations are ecologically distinct from those of vertebrates, often relying heavily on seasonal winds and multiple generations to complete a full annual cycle, due to short insect life spans.
2. Here, we review publicly available online resources to identify key patterns of spatial, taxonomic scales and complexity of climatic responsiveness to environmental predictors in migratory insects.
3. We found that migratory insects respond to various levels of complexity in climatic patterns, and these responses are predicted by life history and ecological traits: (i) responses to climatic effect type were predicted by climate zone(s) of the distribution area, whereas (ii) response to climatic complexity was predicted by body size. In conclusion, migratory insects respond to various levels of complexity in climatic processes, and this responsiveness is governed by a substantially wider array of environmental predictors than demonstrated in vertebrates.
Many factors influence habitat availability and suitability for moths, and the major categories of additional threats are noted here. Most flow directly from anthropogenic activities. Some engender strong conflicts of interest—for example use of pesticides for crop or other commodity protection and introductions of alien species (whether insects as biological control agents or plants as agricultural or forestry crops or as ornamentals)—and are recurrent concerns in insect conservation from possible non-target effects. Each may constitute an independent threat to native insects, or combine with other threats in other ways, often poorly defined.
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.
Effects of fluoride-polluted spruce leaves on nun moth caterpillars (Lymantria monacha)
Leaves of Norway spruce which had received different levels of pollution from an aluminium factory were used as food for nun moth larvae reared under standardized laboratory conditions and under field conditions. Above the control level (7,9 ppm F) concentrations of fluoride up to 365,0 ppm F resulted in detrimental effects to the larvae. Mortality increased by up to 75% and development was considerably delayed. In addition, a reduced growth rate resulted in pupal weights up to 55% below that of the control animals. The maximum factor of fluoride accumulation from the food was 7,3; it was found in larvae that had died during the 5th instar. Fluoride concentrations from pupae indicated that accumulation did not exceed a factor of 3,8. A level of 1400–1500 ± 600 ppm F content of larvae is considered to be lethal. Lower concentrations have been found in surviving pupae. The significance of heavy fluoride pollution of Norway spruce to nun moth epidemics is discussed.
Nadeln von Fichten (Picea abies Karst.), die verschieden stark durch die Fluorwasserstoff-Emissionen eines Aluminiumwerkes belastet waren, dienten als Futter für Nonnenraupen (Lymantria monacha L.). Die Experimente fanden unter standardisierten Laborbedingungen und im Freiland statt. Der Fluorgehalt der Nadeln variierte zwischen 7,9 und 365,0 ppm. Er übte schädigende Wirkung auf die Raupen aus: die Raupenmortalität wurde bis 75% gesteigert, die Entwicklung war beträchtlich verzögert und das verminderte Raupenwachstum führte zu Puppengewichten, die um 55% niedriger lagen als jene der Kontrolltiere. Der höchste Fluor-Akkumulationsfaktor, bezogen auf den F-Gehalt des Futters, betrug bei Raupen, die im 5. Larvenstadium gestorben waren, 7,3; die Fluorgehalte der Puppen zeigten an, daß die Akkumulation in diesen Individuen den Faktor 3,8 nicht überschritten hatte. Der Fluorgehalt der Larven wird als letal angesehen, wenn er den Schwellenbereich von 1400 bis 1500 ± 600 ppm F erreicht. Niedrigere Konzentrationen wurden in überlebenden Puppen gemessen. Die Bedeutung hoher Flurbelastungen von Fichten für die Populationsdynamik von L. monacha wird erörtert.
During 1985-6 the vegetation in the rides (forest tracks) of eight English lowland woods, planted on ancient woodland sites was surveyed. Shade was measured in each transect by hemispherical photography. Dicotyledonous species richness and the majority of dicot plant species declined as shade increased. The results for individual species compare favourably with Ellenberg's (L) value in most cases, and a method is suggested for modifying Ellenberg's data in the light of new information. The woodlands contained species of both open and shaded habitats and communities were influenced by soil acidity. Because shade in woodland rides increases as the trees mature, theory states that there will almost certainly be a reduction in plant species diversity. Butterfly populations would also be adversely affected, partly because of the reduction in direct sunlight, and partly because their larval foodplants decline in both quantity and quality since they are generally associated with low to moderate shade.
Identifying ecological traits that make some species more vulnerable than others is vital for predictive conservation science. By identifying these predisposing traits we can predict which species are most prone to decline and gain an understanding of the reasons behind the decline. The aim of this study was to determine the ecological traits that best predict extinction risk and distribution change in Finnish geometrid moths and to develop an understanding of the biological connections between these traits and threats. We found that larval specificity, overwintering stage and flight period length predicted distribution change and extinction risk. There was also an interaction effect between larval specificity and body size on both distribution change and extinction risk. In monophagous species the host plant distribution predicted extinction risk. Even though ecological traits are known to be important determinants of extinction risk, the IUCN red list categorization system is exclusively based on quantitative measures of populations and ignores the ecological traits. Here, we propose that taxon specific ecological data should also be used to predict extinction risk at least on a regional scale to improve the accuracy of the IUCN extinction risk classification.
Migration rate is often thought to be affected by species distribution, abundance, body size, and niche width, but empirical results are controversial and fragmentary. In this study we examined these relationships in a large assemblage of noctuid moths. Migration rate was measured using two approaches, directly with a mark-recapture study in a network of small islands, and indirectly on the basis of the occurrence of moths outside their breeding habitat. The effects of the factors assumed to affect migration rate were adjusted for taxonomy using a simple yet novel approach based on logistic regression. Both with and without adjusting for taxonomy, the results indicate that abundance and body size influence migration rate, that the effects of abundance and body size have a negative interaction, and that the effects of ecological specialization on migration rate are evident (monophagous species migrate less than oligophagous or polyphagous species). The incidence of island or habitat patch occupancy was not affected by body size, most likely because body size has several contrasting consequences on the processes that determine island occupancy. Migration rate appears to be an evolutionarily labile character, which can readily transform in different phylogenetical lineages of moths.
BERLIN--
Edelgard Bulmahn has been a major force in German science and higher education since becoming research minister in 1998. She
has proposed an overhaul of Germany's university rules--seeking merit pay and "junior professorships" that would free young
scientists to pursue independent research--that has polarized the academic community. In a 9 April interview with
Science
in her Berlin office, Bulmahn discussed these and other topics in laying out her vision for German research.
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.
1. Ecological traps occur when organisms preferentially reproduce in low quality reproductive habitats because the co-evolved cues associated with high quality habitat become re-associated with low quality habitat due to anthropogenically mediated habitat changes. Although the proximate mechanisms underpinning nearly all empirical examples of ecological traps involve exotic species, agriculturalization, or artificial structures, habitat restoration may also facilitate ecological traps because it directly targets species assemblages with a long-standing co-evolutionary history.2. In western Oregon, USA, a locally rare, wetland-restricted population of the butterfly, Lycaena xanthoides, laid more eggs per host plant and more frequently oviposited on Rumex salicifolius growing in seasonally flooded, restored wetlands where survival is approximately seven-fold lower than adjacent non-flooded habitats. Outside of the restored wetlands, Rumex salicifolius is found almost exclusively in non-flooded habitats adjacent to seasonally flooded wetlands.3. In the non-flooded habitat, host plant apparency appears to be reduced by tall, invasive exotic grasses (Festuca arundinacea and Phalaris aquatica), whereas host plants in seasonally flooded, restored wetlands were surrounded by low-growing, native vegetation and bare ground, rendering host plants more physically conspicuous. The devaluing of higher quality host plants by overtopping exotic grasses immediately adjacent to conspicuous low quality host plants in restored wetlands appeared to facilitate an unintended ecological trap for Lycaena xanthoides via inaccurate host plant niche replacement.4. Although there are few published examples of restoration traps, increased scrutiny of restored habitats will be necessary to determine how common and what type of situations facilitate ecological traps.
1. The small tortoiseshell butterfly (Aglais urticae L.) is considered to be a widespread and abundant generalist species in Northern Europe. However, it declined sharply in the U.K. between 2003 and 2008, coinciding with the arrival and spread of a parasitoid, Sturmia bella Meig. (Diptera: Tachinidae), which specialises on nymphalid butterflies.
2. Whether the decline in A. urticae is associated with the arrival of S. bella was investigated using data from a large-scale butterfly monitoring scheme, and by collecting larvae to assess parasitoid incidence and parasitism frequency. Similar data were compiled for a related butterfly (Inachis io) which is also parasitised by S. bella but which is not declining.
3. Sturmia bella was recorded as far north as north Lincolnshire (53.53°N). Aglais urticae has declined significantly to the south of this latitude, but not to the north.
4. Sturmia bella was present in 26% and 15% of the larval groups of A. urticae and I. io, respectively, and now kills more individuals of A. urticae (but not I. io) than any native parasitoid.
5. Survival was 25–48% lower in batches of A. urticae larvae where S. bella was present, indicating that S. bella causes host mortality in addition to that caused by native parasitoids.
6. Our results suggest that S. bella may be playing a role in the recent decline of A. urticae. However, further research is needed to establish its effects relative to other potential drivers of trends in the abundance of this butterfly.