A.A. Grez

University of Chile · Departamento de Ciencias Biológicas Animales

The first step to better understand the relationship between natural enemy communities and pest control is to know which, when, and how frequently different natural enemies interact with their prey. In alfalfa fields of central Chile, aphids are the most common pests and are consumed by predators such as coccinellids, syrphids, and spiders. In this...

Simple Summary As climate change intensifies, understanding the impact of environmental factors on bat activity becomes essential for their conservation. This study, centered in central Chile, utilizes data from automatic bat detectors and climatological stations to explore the effects of air temperature and relative humidity on the timing of activ...

Coccinellids (Coleoptera) are important natural enemies of pests in agroecosystems. However, worldwide, native species face several threats, including landscape simplification, biological invasions, and climate change. In Central Chile, one of the global biodiversity hotspots, coccinellid communities are very diverse and are composed mostly of nati...

The trophic interactions between predators can vary depending on the abundance of their prey. In the alfalfa fields of central Chile, coccinellids (Coleoptera: Coccinellidae) are the main natural enemies of aphids (Hemiptera: Aphididae), whose populations vary throughout the season. Coccinellids can forage for alternative prey, remaining in the cro...

Dryland forests are the areas most threatened by climate change, urbanization and land-use change simultaneously. Ecosystem services provided by Mediterranean dryland forests are have been in steep decline, and are extensively studied in the Mediterranean basin, however considerably less in other areas with Mediterranean climates. Knowledge of thes...

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and...

Citizen science is a valuable tool for early detection, distribution, and spread of invasive alien species (IAS). Nevertheless, citizen science initiatives have several potential biases and may be complemented with long-term structured monitoring schemes. We analyzed the spatial–temporal dynamics of the invasion of Harmonia axyridis (Pallas) (Coleo...

Bat populations are threatened in many regions of the world, partly due to the loss of foraging and commuting habitats in farmland and declines in insect prey populations caused by agricultural intensification. Given that bats play an important role as bioindicators and in suppressing crop pests, it is crucial to mitigate negative impacts that aris...

The forestry practice of clear-cutting (the removal of all woody vegetation) results in a range of negative impacts on ectotherm physiology and behaviour. Organisms in these habitats can experience elevated body temperature due to increases in air and soil temperature, affecting their performance. In this study, we evaluated the effect of ambient t...

Conversion of natural land covers to agriculture is a major cause of the global biodiversity decline. Bats are an important component of biodiversity in agricultural landscapes because they provide pest control services. Although management recommendations towards the enhancement of insectivorous bat populations in agro-ecosystems have previously b...

• A greater taxonomic and functional diversity of natural enemies in agroecosystems is frequently positively associated with more effective pest control, due to the complementarity of species or traits. But this diversity has declined with landscape homogenisation and loss of natural covers, particularly losing native species, which play an importa...

Harmonia axyridis (Pallas) has invaded most continents in the world, including South America. In Chile, it became invasive after 2010, turning into a dominant species in coccinellid guilds in alfalfa crops, where it coexists with the introduced species Hippodamia variegata (Goeze) and the native species Eriopis chilensis Hofmann, the populations of...

1. Conventional intensification of agriculture has reduced the availability of resources for pollinators, reducing their diversity and affecting plant pollination, both in natural habitats and croplands. Field margin floral enhancements such as flower strips or restored field margins could counteract these negative effects. 2. The approaches to a...

The top-down suppression of pest insects by their natural enemies, such as insectivorous bats, represents an important ecosystem service in agricultural systems. Recognizing the importance of bats to suppress pest populations and further conserve their populations near agricultural systems could reduce damage to crops thereby potentially increasing...

We provide a list of coccinellids (Coleoptera: Coccinellidae) species from the island territories of Chile. We report a total of 68 records, coming from ten islands, including 42 species corresponding to more than 35% of the species of the country. This paper presents the first Coccinellidae records for the Islas Desventuradas, Isla Mocha and Isla...

Moonlight intensity influences the activity patterns of bats. Some bat species reduce their activity levels during brighter nights, a phenomenon known as “lunar phobia.” While lunar phobia of bats has been extensively studied in tropical regions, the same is not the case of bats in temperate regions. By using acoustic detectors, we examined differe...

Since the late 19th century, exotic ladybirds (Coleoptera: Coccinellidae) have been used extensively for suppressing herbivorous insects of economic importance. In recent decades, the introduction of non‐native biological control (BC) agents has been greatly limited due to the awareness of the potential non‐target effects of introductions. Nonethel...

The Harlequin ladybird Harmonia axyridis Pallas, native to eastern Asia, is an invasive, non-native species that has recently achieved an almost worldwide distribution. A conspicuous feature of this species is colour polymorphism of the elytra. In its native area, the populations consist of a recessive non-melanic morph, several dominant melanic mo...

Forestry plantations of Pinus radiata, managed through clearcutting method, would offer resistance to the movement of native fauna among remnants of native forest. In this study, we evaluate the possibilities of establishing connectivity corridors for native fauna in a forest landscape dominated by P. radiata, focusing on seven species with some le...

Context Although saproxylic beetles use deadwood in industrial exotic forest plantations, deadwood and historical land use patterns may interact among each other making difficult the implementation sustainable management intended to conserve saproxylic beetle diversity. Objectives We assessed the additive and interactive effects of deadwood and la...

We tested two questions: i) whether the climatic conditions of the Azorean Islands in Portugal may have restricted the invasion of Harmonia axyridis across this archipelago, and ii) determine what population of this species could have a higher probability of invading the islands. We used MaxEnt to project the climate requirements of different H. ax...

La submesa Cambio de Uso del Suelo (CUS) tuvo como objetivo compilar y presentar en un informe la evidencia científica disponible sobre los cambios de uso del suelo y sus impactos en relación con las opciones de mitigación del cambio climático. Esta submesa contó con la participación de más de 30 científicos de diversas áreas de las ciencias ambien...

Landscape composition and heterogeneity are considered important factors for enhancing biodiversity and their associated ecosystem services in human-modified landscapes. Despite their roles in pest suppression in agricultural areas, insectivorous bats have been poorly represented in studies assessing the effects of landscape structural changes, par...

Records of extreme altitudes where several coccinellid species from South America inhabit the Andes of Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru are provided. After an intensive review of several entomological collections and literature, records for 35 species with at least one location over 3500-m elevation were obtained, including t...

The intensive management of tree plantations has replaced and fragmented native forests worldwide. A direct consequence of this activity is the creation of new edges, which generate changes in microclimatic conditions in the adjacent forest as well as in the neighboring clearcut stands left over after harvesting by clearcut logging. Thus, newly cre...

Urbanization alters community composition, frequently leading to decline in native species abundance and richness. Nevertheless, responses might also depend on trait-based local habitat and landscape-scale filters. In this work, we studied how local characteristics of greenspaces and landscape context at 100 and 1000 m influence taxonomic and funct...

The invasion of Harmonia axyridis has had negative consequences on coccinellid assemblages, with a decline in abundance and diversity, but the coexistence of invasive and resident species may depend on the strength of intra- and interspecific exploitative competitive interactions. These antagonistic interactions have been scarcely studied in coccin...

Agricultural intensification is one of the major causes for the global loss of biodiversity and associated ecosystem services. As an alternative to conventional farming, organic management is considered a way to mitigate some of the negative impacts on biodiversity in agricultural landscapes; however, their benefits for bats are not very conclusive...

The harlequin ladybird Harmonia axyridis (Coleoptera: Coccinellidae) has rapidly spread in several continents over the past 30 years and is considered an invasive alien species. The success of H. axyridis as an invader is often attributed to weak control by natural enemies. In this paper, we provide an overview of current knowledge on predators and...

Biological invasions represent a serious menace to local species assemblages, mainly due to interspecific relationships such as competition and predation. One important invasive species worldwide is Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), which has invaded many regions of the world, threatening the native and endemic coccinellid ass...

Global biodiversity monitoring is urgently needed across the world to assess the impacts of environmental change on biodiversity. One way to increase monitoring is through citizen science. ‘Citizen science’ is a term that we use in this chapter to describe the diverse approaches that involve people in monitoring in a voluntary capacity, thus includ...

The replacement of native forests by Pinus radiata plantations modifies habitat availability and quality for wildlife, constituting a threat to species survival. However, the presence of understory in mature pine plantations minimizes the negative impacts of native forest replacement, rendering a secondary habitat for wildlife. Whether forest-dwell...

El fracaso del establecimiento de especies invasoras puede estar influido por características bióticas y abióticas del ecosistema colonizado. El caso de Harmonia axyridis en las islas Azores representa un ejemplo del fracaso de una especie invasora. El presente estudio analiza la influencia de las condiciones climáticas de las Azores en el fracaso...

Harmonia axyridis ha invadido muchas regiones del mundo, produciendo efectos negativos en las comunidades locales de coccinélidos. Varios estudios describen a escala local las consecuencias de esta invasión, sin embargo los estudios de interacción a escala regional son escasos. El objetivo de este trabajo fue estimar la probabilidad de interacción...

Los efectos de la configuración de la vegetación hospedera sobre las poblaciones de insectos herbívoros y de sus enemigos naturales pueden ser diversos, por lo cual es necesario realizar investigaciones específicas para encontrar aplicaciones en el manejo de insectos plagas. En este artículo se evaluó el efecto de la forma del parche y de la vegeta...

This proceedings contains papers dealing with issues affecting biological control, particularly pertaining to the use of parasitoids and predators as biological control agents. This includes all approaches to biological control: conservation, augmentation, and importation of natural enemy species for the control of arthropod targets, as well as oth...

Harmonia axyridis has invaded many regions of the world, with negative effects on local biodiversity, and thus it is of global concern for biological conservation. Recently it has invaded central Chile, one of the world's biodiversity hotspots, where the abundance and richness of ladybird species, particularly native species in agroecosystems, have...

ContextInteractions between landscape-scale processes and fine-grained habitat heterogeneity are usually invoked to explain species occupancy in fragmented landscapes. In variegated landscapes, however, organisms face continuous variation in micro-habitat features, which makes necessary to consider ecologically meaningful estimates of habitat quali...

Palabras Clave: Invasiones biológicas, Coccinellidae, Modelos de Distribución de Especies, Coberturas de suelo. Las invasiones biológicas son una causa importante de extinción de especies nativas a nivel global. Una especie altamente invasora es Harmonia axyridis, de gran voracidad y utilizada a nivel global como controlador biológico de plagas. Es...

Introduction: Biological invasions are one of the major threats to biodiversity. Harmonia axyridis (Coleoptera: Coccinellidae) has invaded many regions of the world, with negative consequences on other coccinellids, including native species. In this work we analyze (1) the spread of H. axyridis in Chile, (2) the overlap in distribution and potentia...

Mediterranean ecosystems have been recognized as a priority for biodiversity conservation due to their high levels of species richness and endemism. In South America, these environments are restricted to central Chile and represent a biodiversity hotspot. The study of saproxylic beetles in this area is an unexplored topic, despite the ecological ro...

Biological invasions are one of the major threats to biodiversity. Usually highly disturbed anthropogenic habitats favour invasion by alien species such as the coccinellid Harmonia axyridis. The spread and impact of this species has been documented in Europe and North America, but no information exists for South America. The aims of this study were...

Aim Biological invasions are one of the major threats to biodiversity. Usually highly disturbed anthropogenic habitats favour invasion by alien species such as the coccinellid Harmonia axyridis . The spread and impact of this species has been documented in Europe and North America, but no information exists for South America. The aims of this study...

The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with co...

A nivel mundial las bases de datos geoespaciales de especies facilitan ampliamente el quehacer científico en conservación biológica. En el caso de los insectos, en Chile existe escasez de datos espaciales que permitan diagnosticar el estado actual de las especies y proyectar su posible estado futuro. En este trabajo se generó una base de datos de o...

Las especies invasoras pueden amenazar la diversidad de especies a nivel local, modificando las interacciones entre los organismos al interior del ecosistema y propiciando la extinción de especies nativas. Harmonia axyridis (Coleoptera: Coccinellidae), originaria de Asia, fue introducida a diferentes países del mundo para el control biológico de pl...

1. Global warming and biological invasions are important threats to biodiversity. Nonetheless, there is little information on how these factors influence performance or life‐history traits of invasive and native species. 2. The effects of temperature on physiological and fitness traits of two invasive alien species ( H armonia axyridis and H ippoda...

Tree plantations may play a role in the conservation of global forest biodiversity. At the landscape scale, plantations with a complex understory may provide surrogate habitats for forest-dwelling organisms. This was tested using a manipulative experiment in which the abundance, movement and survivorship of Ceroglossus chilensis (an endemic and fli...

Inferences about introduction histories of invasive species remain challenging because of the stochastic demographic processes involved. Approximate Bayesian computation (ABC) can help to overcome these problems, but such method requires a prior understanding of population structure over the study area, necessitating the use of alternative methods...

The current trend toward simplification of agricultural landscapes, as well as the associated loss of perennial cover types, can decrease landscape heterogeneity and also natural enemy abundance and diversity, favouring exotic species. We evaluated the effects of agricultural landscape composition and heterogeneity at two different spatial scales (...

South American temperate forests are of special conservation concern due to their highly endemic flora and fauna, and the occurrence of unique plant-animal interactions. Yet, knowledge regarding gall inducers diversity is limited although increasing rapidly in the last two decades. Here, we performed a review of the literature, supplemented with fi...

Crop edges have significant effects on populations of natural enemies, acting as source or sink habitats during the growing season. Previous observations have shown that coccinellid species are associated with thistle (Sylibum marianum (L.) Gaertn), a common exotic weed in the central valley of Chile. To determine whether thistles growing at crop e...

The Convention on Biological Diversity (CBD) expects forestry plantations to contribute to biodiversity conservation. A well‐developed understory in forestry plantations might serve as a surrogate habitat for native species and mitigate the negative effect of plantations on species richness. We experimentally tested this hypothesis by removing the...

Aim Both anthropogenic habitat disturbance and the breadth of habitat use by alien species have been found to facilitate invasion into novel environments, and these factors have been hypothesized to be important within coccinellid communities specifically. In this study, we address two questions: (1) Do alien species benefit more than native specie...

C.M. Villegas, J.A. Verdugo, A.A. Grez, J. Tapia, and B. Lavandero. 2013. Movement between crops and weeds: temporal refuges for aphidophagous insects in Central Chile. Cien. Inv. Agr. 40(2): 317-326. Crop edges have significant effects on populations of natural enemies, acting as source or sink habitats during the growing season. Previous observat...

The effects of forest fragmentation on ecological interactions and particularly on food webs have scarcely been analysed. There is usually less herbivory in forest fragments than in continuous forests. Here we hypothesize that forest fragmentation enhances top‐down control of herbivory through an increase in insectivorous birds and a decrease in he...

Background: Arid and semi-arid environments impose limitations on plant regeneration. This is especially important during biotic dispersal in plants with recalcitrant seeds, in relation to when and where birds disperse these seeds.Aims: We examined the effect of the onset of seasonal precipitation on the regeneration of Cryptocarya alba (Lauraceae)...

Human-assisted introductions, including those in the context of biological control, are considered to be one of the most important factors of global environmental change. However, the mechanisms underlying environmental changes, such as the decrease in the relative abundance of native species, are poorly understood. Since the introduction of the la...

Habitat fragmentation can affect the morphological design of flying insects in different ways through changes in the costs and benefits of dispersal patterns. Larger wings should be favored if necessary resources are scattered across a fragmented landscape. The purpose of this research is to test this prediction in Bombus dahlbomii (Guérin), a nati...

Among the aphidophaga guild present in alfalfa [Medicago sativa L. (Fabaceae)], coccinellids forage on aphids most of the time on the foliage and carabids on the ground. The result of their combined effect can be synergistic, additive, or antagonistic, but this may depend on the prey density and interacting predatory species. In this study, we firs...

Habitat fragmentation can affect the morphological design of flying insects in different ways through changes in the costs and benefits of dispersal patterns. Larger wings should be favored if necessary resources are scattered across a fragmented landscape. The purpose of this research is to test this prediction in Bombus dahlbomii (Guérin), a nati...

In this work, we document the presence of Harmonia axyridis in Chile, an invasive coccinellid species that has had negative effects in other regions of the world, such as: impacts on non-target arthropods, invasions of houses and fruit damage. This species has been found in the last three years in the Metropolitan and Valparaíso regions, in crops,...

Based on their effect on prey populations, predators can interact synergistically, additively, or antago-nistically. Predator attraction by semiochemicals in response to herbivory is well documented; how-ever, the possibility of semiochemicals mediating synergistic interactions has not been explored. Eriopis connexa (Germar) and Hippodamia variegat...

Permanent and permeable edges, where natural enemies can feed, overwinter or easily cross over, should enhance the early arrival of these predators to crops. We evaluated the abundance and species richness of coccinellids migrating to alfalfa fields adjacent to Eucalyptus, a mix of false acacia, blackberries and poplar (F-B-P), vineyards, corn and...

Permanent and permeable edges, where natural enemies can feed, overwinter or easily cross over, should enhance the early arrival of these predators to crops. We evaluated the abundance and species richness of coccinellids migrating to alfalfa fields adjacent to Eucalyptus, a mix of false acacia, blackberries and poplar (F-B-P), vineyards, corn and...

Habitat fragmentation results in new environmental conditions that may stress resident populations. Such stress may be reflected in demographical or morphological changes in the individuals inhabiting those landscapes. This study evaluates the effects of fragmentation of the Maulino forest on population density, sex ratio, body size, and fluctuatin...

We assessed the effect of plant patch shape and surrounding vegetation on the density, emigration, and immigration of predatory coccinellids, and on the density of their aphid prey Brevicoryne brassicae (L.). Between spring 1997 and fall 1999, we set up square and I-shaped patches of Brassica oleracea Plenck surrounded by Medicago sativa L. or Alli...

The gall wasp genus Paraulax (Hymenoptera, Cynipidae) associated with southern beeches (Nothofagus (Nothofagaceae)) from South America is revised. The genus Paraulax and its type species, P. perplexa, are redescribed and a neotype is designated. Two additional species of Paraulax are described as new: P. queulensis and P. ronquisti. After having be...

The gall wasp genus Paraulax (Hymenoptera, Cynipidae) associated with southern beeches (Nothofagus (Nothofagaceae)) from South America is revised. The genus Paraulax and its type species, P. perplexa, are redescribed and a neotype is designated. Two additional species of Paraulax are described as new: P. queulensis and P. ronquisti. After having be...

FIGURE 2. Paraulax perplexa: (A) Head anterior view. (B) Head posterior view. (C) Female antenna. (D) Detail of last flagellomeres. (E). Male antenna. (F) Detail of basal flagellomeres. (G) Mesosoma lateral view. (H) Pronotum anterior view. (I) Mesosoma dorsal view.

FIGURE 3. Paraulax perplexa: (A) Propodeum. (B) Fore leg, arrow pointing to swelling of profemur (C) Magnification of the structure of rows of sharp, closely spaced, deep costulae. (D) Metatarsal claw. (E) Forewing. (F) Female metasoma and (G) Detail of ventral spine of hypopygium. (H) Male metasoma.

FIGURE 4. Paraulax queulensis n. sp. and Cecinothofagus ibarrai n. sp.: (A – H) P. queulensis: (A) Habitus lateral view. (B) Head and mesosoma lateral view. (C) Mesosoma dorsal view. (D) Metatarsal claw. (E) Ventral spine of hypopygium. (F) Female antennae. (G) Male antenna. (H) Forewing. (I – K) Cecinothofagus ibarrai. (I) Male antenna. (J) Mesoso...

FIGURE 8. Cecinothofagus gallaelenga n. sp.: (A) Head anterior view. (B) Female antenna and (C) detail of apical flagellomeres. (D) Male antenna. (F) Head posterior view. (G) Pronotum anterior view. (H) Forewing.

FIGURE 14. The 50 % Majority-rule consensus tree from the Bayesian analysis of the two genes (28 S, COI) combined. Numbers on branches indicate posterior clade probabilities (only values between 0.50 and 1.00 are given). Current suprageneric classification is given to the right.