Successful conservation biological control programs require a good understanding the nutritional ecology of natural enemies to maximize their field efficacy. This study evaluated the effects of non-floral sugar sources on fitness parameters of Mastrus ridens, a specialized parasitoid of the codling moth. In the laboratory, we compared the longevity, parasitism, and reproduction of adult parasitoids exposed to different sugar sources, including Vicia faba extrafloral nectar, honeydew from several hemipteran species, diluted honey (positive control), and no-sugar controls. We also tested the effects of exposing parasitoids to honey for only 24 h. The results showed that sugar availability and source type significantly affected parasitoid performance. Extrafloral nectar was better than mealybug honeydew, with female offspring numbers similar to those exposed to honey, and increased the number of parasitized host larvae by up to 3.5-fold compared to no-sugar conditions. The effects of honeydew effects on male longevity were variable, possibly explained by its composition, and the mode of presentation. Parasitoids with a short exposure to high-quality sugar performed poorly. Our findings indicate that successful conservation and augmentative biological control programs using this species require field provision of high-quality, accessible sugar resources.

Sweet cherry production relies heavily on managed and wild insect pollinators. Pollination success depends not only on the presence of flower visitors but also on their behaviour and traits. Although Chile is among the world's leading cherry producers, information on the diversity and pollination roles of insect visitors in its orchards remains scarce. In this study, we used video monitoring to assess the foraging behaviour of floral visitors in 16 conventional orchards in central Chile. In 2023, we recorded 3012 insect visits. Bees comprised 65% of visits, with honey bees ( Apis mellifera ) alone accounting for 64% and fewer than 1% for wild bees. Besides, 33% of the visits were attributed to flies—mainly Dilophus sp. (Bibionidae) and several syrphid species—and 2% to beetles. Bees spent the shortest time per flower, exhibited greater inter-floral movement and contacted the stigma most frequently, behaviours associated with high pollination potential. In contrast, flies and beetles typically remained longer on flowers, moved little between them and often consumed floral resources without making contact with the stigma. These behavioural patterns suggest that hymenopterans are the most effective pollinators in these systems. Nevertheless, the high abundance of flies in the orchards may partly compensate for their limited pollination efficiency. Additionally, we found a significant positive relationship between body size and the likelihood of stigma contact, highlighting a key morphological trait associated with pollination effectiveness. The overall low diversity and small size of floral visitors in these conventional cherry orchards may explain why few of the species present have the potential to be effective pollinators. Promoting practices that enhance bee floral visitor diversity could increase the presence of alternative pollinators, reduce reliance on managed honeybees and contribute to more stable cherry yields.

Coccinellids are important biocontrol agents which are threatened by agricultural intensification and landscape change. Their responses to the landscape are inconsistent which may be due to a taxonomic focus of studies that misses the traits that drive the differences in species responses to the landscape. In this study, we investigated how coccinellids in alfalfa respond to environmental variables in terms of their traits. We examined five traits: body size, activity period, habitat specialization, spatial ubiquity and dispersal habits, and analysed how single and multiple traits (syndromes) are affected by local variables (aphid density), and landscape compositional (diversity of land uses) and configurational heterogeneity (edge density), at two spatial scales (500 and 1500 m). The community-weighted mean of all traits, except body size, was affected by landscape heterogeneity, mostly at the smaller spatial scale. Coccinellid communities break into two groups of trait syndromes in their response to landscape heterogeneity. Smaller species, uncommon in alfalfa, mostly native, were negatively associated with compositional and configurational heterogeneity at both spatial scales, while the remaining species were associated with increased landscape heterogeneity. This latter group of species splits into two groups at the smaller spatial scale, composed by large exotic and natives, distributed along a gradient of landscape configurational heterogeneity. The response of ladybeetles to landscape composition and configuration depends more on their traits than on their origin (native vs. exotics). These responses should be considered when designing policies for agricultural landscape management, depending on the conservation aims.

Habitat manipulation through non-crop vegetation management is a strategy in conservation biological control, and using native plants is attractive because they can also help in biodiversity conservation. The potential for nectar provision of 13 flowering species native to Chile, and two introduced, was evaluated considering Mastrus ridens (Hymenoptera: Braconidae). Nectar availability was studied through flower phenology, accessibility through flower and parasitoid morphology, and suitability through longevity when exposed to nectar solutions or cut flowers. Most species had long flowering periods, potentially making nectar available when adults are active, but they differed in nectar accessibility and profitability. Of the 13 native species, nectar was easily accessible for M. ridens in Cistanthe grandiflora, Sphaeralcea obtusiloba, Andeimalva chilensis, and Lycium chilense. None of the nine native species tested with nectar solutions increased longevity, but with cut flowers, parasitoids lived longer with the natives Teucrium bicolor and S. obtusiloba, and the introduced Fagopyrum esculentum, making them candidates for M. ridens conservation. Females lived longer with cut flowers of T. bicolor and S. obtusiloba than with their nectar solutions. In conclusion, using the native flowering species Teucrium bicolor and Sphaeralcea obtusiloba in agroecosystems can serve biological control and biodiversity conservation.

Ants (Hymenoptera: Formicidae) are a diverse and ecologically important group of social insects that play crucial roles in ecosystems worldwide. In this study, we aim to identify the community of ant species present in two important fruit crops of Central Chile. Ants were sampled from January to March in three cherry orchards and three vineyards, using standard pitfall traps to sample above-ground, and subterranean pitfall traps to sample below-ground. We found in total seven species of ants, three native and four introduced, with Strumigenys silvestrii Emery, 1906 being the first record of Attini species for central Chile. The introduced Hypoponera eduardi (Forel, 1894) was the most frequently sampled species, while the invasive Linepithema humile (Mayr, 1868) was found in only two sites. The ecological or functional roles of these species within the Chilean agroecosystems deserve further investigation.

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 native species, which are most common in less disturbed habitats. In alfalfa fields, native coccinellids play a crucial role in the biological control of aphids, even when they are less abundant than exotics. However, in the last 2 decades, native species in this crop have declined in abundance and diversity. Our long-lasting field and laboratory studies have shown that this decline is associated with: (1) the invasion of Harmonia axyridis (Pallas), which has superior competitive abilities and escapes more from parasitism; (2) the simplification of agricultural landscapes, loss of natural habitats, and urbanization; and (3) increasing environmental temperatures and decreasing precipitation. The decline in native coccinellid populations has resulted in a loss of taxonomic and functional diversity of assemblages, which may jeopardize biological control. Alfalfa fields and natural and semi-natural habitats may offer an opportunity for the conservation of native coccinellids in agricultural landscapes. Such conservation might be achieved with better management of alfalfa fields and surrounding areas. Worldwide, native coccinellids (Coleoptera) face multiple threats. In Central Chile, coccinellid communities are diverse, with mostly native species. However, they have declined because of (1) invasion of Harmonia axyridis, (2) simplification of agricultural landscapes, natural habitats loss, and urbanization, and (3) increasing temperatures and decreasing precipitation. The decline in native coccinellids has resulted in lower taxonomic and functional diversity of assemblages, jeopardizing biological control. Alfalfa fields and natural and semi-natural habitats may offer an opportunity for their conservation in agricultural landscapes.image

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 study, through video recording, we analyzed how natural enemy communities visiting aphid sentinel cards vary between scenarios of low and high abundance of aphids in alfalfa in spring. On 15 occasions, during the day, we monitored the natural enemies visiting cards with sentinel aphids (60 cards per field; total 900) located in fields with high (n = 6) and low (n = 9) aphid abundance. We also analyzed whether the abundance of coccinellid species visiting sentinel cards was related to their abundance in each field. In 750 h of video recording, we found 2749 natural enemies visiting the sentinel cards; 86.2

AbstractThe study of insect reproduction is important from both basic and applied perspectives, particularly in mealybugs (Hemiptera: Pseudococcidae), because of the diversity of reproduction modes and also because they are important agricultural pests. Sex pheromone control strategies are currently being developed for many species. Pseudococcus calceolariae (Maskell) and Pseudococcus longispinus (Targioni Tozzetti) are closely related species that often coexist in the same host plant. In this study, mating behavior, the possible occurrence of asexual reproduction, and hybridization between them were investigated. We confirmed that both species did not show asexual reproduction and required the presence of a male to reproduce. When couples of the same species were put together, males had a highly stereotyped mating behavior, and females showed an active role in mating success by accepting or rejecting males with abdominal movements. In hybridization trials, no progeny was obtained for any of the interspecific combinations. Moreover, in interspecific pairs, males mainly moved randomly in the arena without direct contact with females and females showed no willingness to mate, escape, or not move in the presence of the male. Therefore, courtship and copulation success in both species were directly related to the specificity of the mating pair and, there was no evidence of hybridization. This information is useful for the understanding of reproduction in this family and supports the development of management techniques based on sex pheromones to disrupt reproduction or to monitor these mealybug species populations.

Habitat or vegetation manipulation is a strategy within conservation biological control, yet, its formal study is relatively recent and lacking in many parts of the world, particularly when using native plants. We found 56 studies dealing with native plants and conservation biological control, from 2002 to 2022. Most were carried out in developed countries, and studied the provision of flower resources to natural enemies' complexes in several crops. The main gaps in knowledge, similar to studies with non-native plants, were the lack of understanding mechanisms, unknown effects on pest populations, and absence of cost-benefit analyses. Breaching these gaps will allow this strategy to be more transferable among cropping systems and locations and will promote its use by farmers.

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 crops when target pests are scarce, favoring their presence before the pest arrives and improving biological control. Therefore, knowledge of the different predator–prey interactions in different scenarios of prey availability has gained great importance. Based on DNA metabarcoding analysis, we describe the diet of the most abundant coccinellid species in alfalfa fields and how food web varies in scenarios of higher and lower aphid abundance. Additionally, we analyzed the consumption of alternative prey, such as pollen. The results revealed a set of generalist predators with high stability in their trophic interactions regardless of aphid abundance. However, Hippodamia variegata (Goeze) is less generalist than Eriopis chilensis Hofmann and Harmonia axyridis (Pallas). The native E. chilensis has a stable consumption of aphids, and other important pests are exclusively preyed by this species. Pollen is frequently consumed by these coccinellids, E. chilensis and H. variegata , which remain in alfalfa throughout the season, increasing its consumption during periods of lower aphid abundance. Aphids are the key prey for the permanence of H. axyridis in these crops. This study shows that coccinellids consume a variety of prey and alternative resources, allowing some species to persist in the fields when aphids are scarce.

The study of insect reproduction is important from both basic and applied perspectives, particularly in mealybugs (Hemiptera: Pseudococcidae), because of the diversity of reproduction modes and also because they are important agricultural pests. Sex pheromone control strategies are currently being developed for many species. Pseudococcus calceolariae (Maskell) and Pseudococcus longispinus (Targioni Tozzetti) are closely related species that often coexist in the same host plant. In this study, mating behavior, the possible occurrence of asexual reproduction, and hybridization between them were investigated. We confirmed that both species did not show asexual reproduction and required the presence of a male to reproduce. When couples of the same species were put together, males had a highly stereotyped mating behavior, and females showed an active role in mating success by accepting or rejecting males with abdominal movements. In hybridization trials, no progeny was obtained for any of the interspecific combinations. Moreover, in interspecific pairs, males mainly moved randomly in the arena without direct contact with females and females showed no willingness to mate, escape, or not move in the presence of the male. Therefore, courtship and copulation success in both species were directly related to the specificity of the mating pair and, there was no evidence of hybridization. This information is useful for the understanding of reproduction in this family and supports the development of management techniques based on sex pheromones to disrupt reproduction or to monitor these mealybug species populations.

Generalist predators can enhance biological control by filling unique niches and complementing other natural enemies, or disrupt it by preying upon other predators and parasitoids, complicating their net value for biological control. We searched for evidence of complementarity and/or interference between native (primarily Eriopis chilensis and E. eschscholtzi) and exotic (primarily Hippodamia variegata and Harmonia axyridis) lady beetles attacking aphids in alfalfa (Medicago sativa) fields near Santiago, Chile. Across 60 fields and three growing seasons, exotic lady beetle adults and larvae reached peak abundance relatively earlier in the growing season than the natives. Furthermore, exotic lady beetle peaks aligned more closely with aphid peak abundance than did native lady beetle peaks. Abundances of native lady beetle adults and larvae were weakly positively correlated with those of exotics, and peak aphid densities were generally lowest in fields where native and non-native lady beetle adults were similarly abundant. Therefore, we did not see evidence of strong interference between exotics and natives. Natural-agricultural habitat edges reduced native, but not exotic, larval lady beetle lag behind aphid peaks and was associated with greater lady beetle and lower aphid densities. Moreover, farms embedded in landscapes with greater natural habitat cover supported more exotic, but not native, lady beetles, and increased the lag between larval lady beetles and aphids for natives but not exotics. These findings support the idea that farms embedded within mosaics of natural and agricultural habitats may provide greater interaction potential between native lady beetles and aphid pests on farms as they move across the landscape, leading to greater top -down control. In contrast, exotic lady beetle lags were unaffected by landscape composition or configuration, but their greater densities in farms surrounded by more natural habitats might reflect a 'concentration effect' whereby exotic lady beetle abundance becomes concentrated in the agricultural habitats that they prefer. Our findings suggest that some lady beetles introduced for biocontrol may be better adapted to intensively managed habitats than natives, possibly leading to spatiotemporal complementarity between native and exotic lady beetles.

Populations of natural enemies in classical biological control programs often undergo recurring bottlenecks during importation and rearing, which can result in lower genetic variability and fitness. Enriching colonies with wild individuals, multiple importations or combining populations from different origins may help reduce this problem. Mastrus ridens (Hymenoptera: Ichneumonidae), a gregarious idiobiont ectoparasitoid of codling moth (Cydia pomonella) larvae was introduced to New Zealand from laboratory colonies dating to the 1990s. To improve populations for release, individuals from a most recent collection were imported from Chile (CL). Tests were conducted to measure genetic diversity of the parental populations (F0) and fitness traits of pure and mixed combinations of NZ and CL populations for F0 and the F1 generations. Results showed several effects depending on the population origin. CL females and males in the F0 generation lived longer than NZ females and males. Offspring from a CL mother lived longer than those from a NZ mother, and F0 and F1 females from a CL mother parasitized more larvae than females from a NZ mother. Genetic diversity estimates of F0 CL and NZ populations were 24% and 17% heterozygosity, respectively, and the NZ population had a larger proportion of diploid males than the CL population. Thus, no improvement in reproductive output resulted by mixing NZ and CL populations, as hypothesized, but a maternal effect was found in this species. This study shows the importance of understanding and tracking imported populations' genetic diversity and fitness traits in classical biological control programs.

Applied Ecology Research Group, School of Life Sciences, Anglia Ruskin University, Cambridge, UK Facultad de Agronomia e Ingenieria Forestal, Pontificia Universidad Catolica de Chile, Santiago, Chile Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile Research Institute for Nature and Forest (INBO), Brussels, Belgium Walloon Agricultural Research Centre (CRA-W), Gembloux, Belgium UK Centre for Ecology and Hydrology, Wallingford, UK Centre for Ecology, Evolution and Environmental Changes and Azorean Biodiversity Group, Faculty of Sciences and Technology, University of the Azores, Ponta Delgada, Portugal

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) (Coleoptera: Coccinellidae) in Chile, based upon two citizen sciences databases (WEB and INAT) and one structured monitoring (SAG). We collected 8638 H. axyridis occurrences between 2009 and 2020. WEB had a higher number of records than SAG and INAT, and in all databases, the number of records has increased over time. The three databases showed that the invasion started in central Chile and then spread toward the north and south. The WEB and SAG recorded occurrences in the extreme north and south, whereas INAT concentrated all the occurrences in a more limited area, included in WEB and SAG. Both citizen science initiatives concentrated their records in areas of high human populations whereas SAG records had a more even distribution across regions. At 2020, WEB accounted for 55

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 the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.

The rhodesgrass mealybug, Antonina graminis (Maskell, 1897), is reported for the first time from Chile, in the northern region of Tarapacá. This legless mealybug is widely distributed in tropical and subtropical regions around the world, and yet mentioned in the neighbouring countries. It feeds on a large variety of grasses (Poaceae), and can be considered as pest. The species identification was based on morphological and molecular data using the 28S gene as barcode marker. Of the five sites sampled, A. graminis was found in only one, indicating it may correspond to a recent introduction. Thus, it would be important to survey more closely its distribution within the country. A key to the genera of Pseudococcidae from Chile is provided, including relevant genera considered as pest, and not established in the country. This key is of direct interest to stakeholders in Chile, such as national phytosanitary services, and farm advisors.

Breeding natural enemies to generate populations with improved characteristics is an attractive idea, particularly nowadays with the increase in use of biological control and the availability of modern molecular and genetic tools. A first step in the process is to characterize traits which can be important for biological control and their intraspecific variation. In this study we characterized fecundity, longevity and dispersal-related traits of four endogamic and three exogamic laboratory populations (lines) of Mastrus ridens, an important parasitoid of the codling moth (Cydia pomonella (L.)). We found that several traits were positively correlated and that there was variability among lines and between endogamic and exogamic lines. Exogamic lines presented a better combination of trait values than endogamic lines. The absence of trade-offs among the traits studied in M. ridens would be advantageous for a breeding program. Nevertheless, it would be important not to lose genetic variability in the process, because of the presence of complementary sex determination (CSD) and negative effects of inbreeding on other traits. The results of this study could be useful for the selection of M. ridens lines with better traits and as preliminary information for breeding programs.

Due to typesetting errors, Table 5 was not displayed correctly in the initial online publication. The original online article has been corrected.

Flower strips can promote and conserve beneficial insects in agroecosystems. Knowing which groups are favoured and which plant traits affect visitation rates by beneficial insects is important for the design of plant strips. We established 21 Native Flower Strips (NFS) in avocado orchards in Central Chile. NFS contained 7–11 plant species, with variable corolla length and flowering period, to promote beneficial insects. We assessed flight activity of ladybirds (Coccinellidae) and bees (Apiformes) in sites adjacent to and far from NFS within avocado orchards. Additionally, we evaluated flower visitation for the main flower visitor groups (Apiformes, Lepidoptera, Diptera, and Coleoptera) to the plant species in NFS according to season and corolla length. We found almost six times greater flight activity of coccinellids and bees in NFS than sites far from NFS within avocado orchards. Visitation rates of pollinator groups varied according to corolla length and season. Diptera, Coleoptera, and Lepidoptera consistently visited short corolla flowers. NFS were highly visited in summer and autumn, when avocados were not in bloom. NFS in orchards should be encouraged by policymakers because they support beneficial insects that could deliver ecosystem services and contribute to local biological conservation.