Insect Resources Research Articles

Multiscale spatial analysis of two plant–insect interactions: effects of landscape, resource distribution, and other insects

ContextBiotic resource exploitation is a critical determinant of species’ distributions. However, quantifying resource exploitation patterns through space and time can be difficult, complicating their incorporation in spatial ecology studies. Therefore, understanding the local drivers of spatial patterns of resource exploitation may contribute to better large-scale species distribution models.ObjectivesWe investigated (1) how the resource exploitation patterns of two trophic interactions (plant–insect) are explained by insect behaviour, resource aggregation, and potential insect-insect interactions. We also analyzed how (2) resource patch size and (3) resource accessibility in a heterogeneous landscape affected host exploitation patterns.MethodsWe quantified nectar robbing by insects in the genus Bombus (bumblebees) and seed predation by Brachypterolus vestitus larvae (Antirrhinum beetle) on Antirrhinum majus L. (wild snapdragons) in the Pyrenees Mountains, Catalonia, Spain. We tested hypotheses about resource exploitation by integrating spatial analyses at multiple scales.ResultsBoth trophic interactions were aggregated, explained by the aggregation of their resource. At some scales, nectar robbing is more aggregated than the resource. Trophic interaction abundance is proportional to resource patch size, following the ideal free distribution model. Landscape features do not explain the locations exploited. Nectar robbing and seed predation occur together more often than expected.ConclusionsOur findings suggest that multiple biotic and ecological spatial factors may simultaneously affect resource exploitation at a local scale. These findings should be considered when developing agricultural projects, management plans and conservation policies.

A novel sustainable photo/chemical magnetic nanomaterial effectively mitigates the allergenicity of phospholipase A2

Reducing the allergenicity of edible insects is crucial for the comprehensive utilization of insect resources. Phospholipase A2 (PLA2) exists in various edible insects and mammalian tissues, which can cause serious allergic reactions. Herein, we constructed a magnetic nanocomposite with photo/chemical synergistic capability to mitigate the allergenicity of PLA2. The formation of prepared nanocomposite was systematically confirmed using various techniques. The nanocomposite exhibited uniform diameters, abundant functional groups, excellent magnetic capabilities. An effective photo/chemical method was established to reduce the allergenicity of PLA2 in vitro. The feasibility of the method was demonstrated through circular dichroism, fluorescence spectrum and IgE-binding analysis. The allergenicity and IgE-binding effect of PLA2 were significantly reduced due to conformational changes after nanomaterial treatment. These results demonstrate the sensitivity and effectiveness a strategy for reducing PLA2 allergenicity, providing a basis for development of nanomaterials to reduce the risk of novel food allergies in response to edible insect products.

Home sweet home: Evaluation of native versus exotic plants as resources for insects in urban green spaces

Abstract Insect decline and loss of biodiversity not only affect large‐scale agricultural landscapes, but are increasingly recognized in urban environments. It is undisputed that a greater supply of flowers in urban green spaces can provide insects with more food and habitat. However, it is still controversial whether native wild plants or non‐native ornamental plants and varieties are the right choice. To answer this question we investigated the number of insects interacting with different types of plants: twelve ornamental and six related wild perennials. In this context, the number of flower visitors per plant species and plot was recorded at 10‐minute observation intervals, as well as the feeding damage caused by insect herbivores on the leaves and stems of the study plants. We established 18 plant species in ten independent study plots in the city of Darmstadt, Germany. The plants were six native wild plant species, six ornamental plant species related to the wild plants from the same genus or family and six exotic ornamental plant species from other genera and families than the wild plants. Native insects (wild bees, flies, beetles, wasps) that feed on pollen and nectar visited wild perennials significantly more often (67% of all visits) than related ornamental (24%) and unrelated exotic plants (9%). In contrast, honey bees (Apis mellifera) showed no preferences to any of the three target plant groups and interacted with other plant species than most of the native insects in our study according to analyses of interaction networks. The assessment of leaf damage caused by insect herbivores on the individual plants confirmed a similar and significant difference in the insects' choices. Leaves from wild plants showed the highest herbivory (mean 2.3% of the leaf area), followed by related ornamental plants (0.8%), whereas unrelated exotic plants were hardly consumed (0.1%) by herbivores. Practical implication. Our study shows that in urban green spaces, both flower‐visiting and leaf‐feeding insects are more likely to use native wild plants as a food source than closely related and exotic ornamental plants.

Fruiting trees provide fruit and insect resources for four tropical deer species

AbstractFruiting trees provide important fruit and seed resources for various animal species, but rarely are they considered to be rich sources of insects as well. During a study of seed dispersal of Trewia nudiflora (Euphorbiaceae) using camera traps in Nepal, we observed four tropical deer species (Axis axis, Muntiacus vaginalis, Rusa unicolor, Axis porcinus) foraging for insects, rather than fruits under the trees. These herbivorous deer are proven seed dispersers of Trewia, but 8%–38% of video captures (across each species) were of insectivory, rather than frugivory. The deer chased and consumed red cotton bugs (Dysdercus sp. family Pyrrhocoridae), which were seed predators that hoarded Trewia seeds. It is likely that other unidentified insect species were also consumed. Tropical deer species are considered to be fully herbivorous, so our observations extend their known diets and possibly indicate a seasonal requirement for protein. These findings also highlight tri‐trophic interactions among deer, insects, and fruits that could have important implications for seedling recruitment if seed predators are being consumed by seed dispersers (in addition to fruit consumption).

FIRST RECORD OF A TORYMIDAE INFESTATION IN THE SEEDS OF CORDIA MACLEODII HOOK. F. & THOMSON: INHIBITING SEED GERMINATION

Background: The seed germination percentage was found to be very low; hence, the investigation was carried out to find out the seed infestation. Aim and Objective: To discover the cause of the low percentage of seed germination. To report the Torymidae infestation in Cordia macleodii Hook. F. & Thomson. Material and methods: Mature fruits and seeds were collected from 10 plants of two selected localities. Longitudinal sections were taken to determine the infection in buds, immature, mature fruits and seeds. Documentation of different stages was recorded. Identification and authentication were performed based on characters observed and reports from ICAR- National Bureau of Agricultural Insect Resources, Bangalore. Discussion: The insect species was identified as a species belonging to the Family Torymidae (Hymenoptera: Chalcidoidea). The fruits of Cordia macleodii Hook. F. & Thomson showed internal as well as external infestation. Conclusion: The investigation's findings confirmed that the low seed germination is due to the infestation of the Torymidae insect, which was reported in this communication for the first time.

Diversity pattern of insects from Macao based on an updated species checklist after 25 years.

Insects represent one of the most diverse groups in the organism world with extremely rich species and morphological diversity, playing important roles in natural and city ecosystems. Regional compilation of insect species lists helps to clarify the richness of insect species in a region, enhances our understanding the structure and function of a local ecosystem and promotes the protection and development of insect resources. Moreover, it also serves as a valuable reference for cities with small area, large population and high urbanisation like Macao. Macao (Macau) Special Administrative Region (SAR) is situated at the Pearl River Delta on the southeast coast of mainland China. With urban development accelerating at great rate in a quite restricted area, Macao still has rich fauna, within which the insect diversity is surprisingly high. In this study, we systematically sorted out major references items of manuals or handbooks, monographs, articles, dissertations, official websites and other publicly available information sources about the insects recorded in Macao and, thus, generated a checklist of 15 orders, 166 families, 868 genera, 1,339 species and 118 subspecies. During this process, the preliminarily summarised list was re-examined to eliminate synonyms and invalid species, based on many more extensive literature reviews. Besides, spelling errors of scientific names, authors and years were corrected. Meanwhile, the catalogue revealed a different composition pattern of species diversity between orders from those of the world and China. Even based on the most conservative estimates, the number of insect species in Macao should not be lower than 3,340 species, which hints at the necessity of deeper investigations with adequate collecting in the future to achieve more comprehensive recognition and understanding of Macao's insect biodiversity.

2018–2021年湖北省恩施市烟田瓢虫、食蚜蝇数据集

Tobacco is a pillar industry in Enshi City, Hubei Province. However, in recent years, the increasing impact of diseases and pests on the yield and quality of tobacco leaves has been growing in Enshi due to climate change and the expanding scale of agricultural planting. Making good use of natural enemies is crucial for implementing green pest control and effectively reducing the negative effects of pesticides, which holds great significance for the sustainable development of the environment in Enshi. Coccinellids and Syrphidae, as important natural enemy resources, exhibit great potential for natural pest control. In order to evaluate the species and population dynamics of Coccinellids and Syrphidae in Enshi, we collected data on natural enemy insect resources from Enshi’s tobacco fields from late 2018 to late 2021 in the paper. All the data were obtained from five Malaise traps. The research covers the specimens of 1,079 predatory Coccinellids and 4,286 Syrphidae. Among them, 26 species of Coccinellids were collected, with 20 species and 6 genera identified. Additionally, there were 23 species of Syrphidae, with 18 species and 5 genera identified. The screening and identification of natural enemy insects were completed by professionals to ensure the data quality. The dataset provides information on the species, quantity, and different parts of the species of Coccinellids and Syrphidae natural enemies, along with specimen bottle photos. It can serve as theoretical basis for implementing comprehensive pest control strategies and using the natural enemy resource in tobacco fields.

The Consumption and Diversity Variation Responses of Agricultural Pests and Their Dietary Niche Differentiation in Insectivorous Bats.

Insectivorous bats are generalist predators and can flexibly respond to fluctuations in the distribution and abundance of insect prey. To better understand the effects of bats on arthropod pests, the types of pests eaten by bats and the response of bats to insect prey need to be determined. In this study, we performed DNA metabarcoding to examine prey composition and pest diversity in the diets of four insectivorous species of bats (Hipposideros armiger, Taphozous melanopogon, Aselliscus stoliczkanus, and Miniopterus fuliginosus). We evaluated the correlation between bat activity and insect resources and assessed dietary niche similarity and niche breadth among species and factors that influence prey consumption in bats. We found that the diets of these bats included arthropods from 23 orders and 200 families, dominated by Lepidoptera, Coleoptera, and Diptera. The proportion of agricultural pests in the diet of each of the four species of bats exceeded 40% and comprised 713 agricultural pests, including those that caused severe economic losses. Bats responded to the availability of insects. For example, a higher abundance of insects, especially Lepidoptera, and a higher insect diversity led to an increase in the duration of bat activity. In areas with more abundant insects, the number of bat passes also increased. The dietary composition, diversity, and niches differed among species and were particularly significant between H. armiger and T. melanopogon; the dietary niche width was the greatest in A. stoliczkanus and the narrowest in H. armiger. The diet of bats was correlated with their morphological and echolocation traits. Larger bats preyed more on insects in the order Coleoptera, whereas the proportion of bats consuming insects in the order Lepidoptera increased as the body size decreased. Bats that emitted echolocation calls with a high peak frequency and duration preyed more on insects in the order Mantodea. Our results suggest that dietary niche differentiation promotes the coexistence of different bat species and increases the ability of bats to consume insect prey and agricultural pests. Our findings provide greater insights into the role of bats that prey on agricultural pests and highlight the importance of combining bat conservation with integrated pest management.

New insights on the spore dispersal of Phallus indusiatus s.l. (Basidiomycota, Phallaceae) for the Brazilian Amazon forest

Spore dispersal by insects (entomochory) is a crucial relationship for phalloid fungi, as mycophagous insects carry large amounts of spores and assist stinkhorns in the colonization of new sites. Phallus indusiatus s.l. is a widely distributed fungal species (Basidiomycota), which recruits generalist mycophagous insects as dispersal agents for their spores. Given the lack of knowledge about the natural history of this relationship, it is assumed that its spores are mostly dispersed by insect feces. This study was conducted in a fragment of Amazon forest in Pará, Brazil, and we (i) identified the insects that visited P. indusiatus s.l., (ii) observed the behavior of the insects during this interaction, and (iii) counted the spores carried both on the body surface and in the stomach of the visiting insects. A total of 333 insects associated with six P. indusiatus s.l. basidiomes were recorded. Stingless bees devoted the most time to foraging and were the insects that carried the largest amount of spores, >83 million spores on the body surface and >60 million in the stomach. Wasps presented low abundance, with five minutes dedicated to foraging, carrying just over 7 million spores on the body surface and >2 million in the stomach. The beetles, although possibly sheltering in the basidiomes before the total maturation of P. indusiatus s.l., were the insects with less carried spores, 189,000 spores on the body surface and about 39,000 spores in the stomach. However, they were the most abundant insects among visitors, surpassing the 100 individuals in a single basidiome. Stinkhorns are very valuable resources for forest insects and these fungi take advantage of this interaction to disperse their spores via feces, but mainly by the body surface of visitors.

Inocellia (Amurinocellia) calida (Raphidioptera, Inocelliidae) was first observed as a predator of Monochamussaltuarius (Coleoptera, Cerambycidae) in China, the vector of Bursaphelenchusxylophilus (Aphelenchida, Aphelenchoididae).

Monochamussaltuarius Gebler (Coleoptera, Cerambycidae) serves as the primary carrier of Bursaphelenchusxylophilus (Steiner & Buhrer) (Aphelenchida, Aphelenchoididae) in the middle-temperate zone of China. Pine wilt disease caused by B.xylophilus leads to serious losses to pine forestry around the world. It is necessary to study the biological control of M.saltuarius to effectively prevent the further spread of B.xylophilus. To explore the insect resources that act as natural enemies of M.saltuarius, investigations were conducted on natural enemy insects by splitting Pinuskoraiensis Siebold & Zucc (Pinales, Pinaceae) damaged by M.saltuarius and dissecting their trunks in Yingpan Village, Fushun County, Fushun City, Liaoning Province, China, in 2023. A larva of Inocellia (Amurinocellia) calida (H. Aspöck & U. Aspöck) (Raphidioptera, Inocelliidae) was discovered in the trunk of an infested P.koraiensis. Additionally, the feeding habits of I.calida were preliminarily examined under indoor conditions and a description of its morphological characteristics was provided. When placed in an indoor environment, the I.calida larva began pupating after a period of 21 days, during which time it consumed and attacked a total of 23 M.saltuarius larvae. Ultimately, after a pupal period of ten days, the I.calida larva emerged successfully as an adult. This discovery marks the first recorded presence of I.calida in Liaoning Province and the first documentation of I.calida in China, serving as a natural predatory enemy of M.saltuarius.

Atração de rola bosta (Coleoptera: Scarabaeinae) a excremento de arapaçu pardo (Aves: Dendrocolaptidae) na Amazônia central

ABSTRACT Bird droppings are an unusual food resource for coprophagous insects and used mostly by opportunistic decomposers. Among them, dung beetles feed mainly on dung, although the species differ in their trophic plasticity. Here we report a record of a dung beetle, Canthidium cf. gracilipes, reaching and manipulating the dropping of a passeriform bird, Dendrocincla fuliginosa (Dendrocolaptidae). The behavior was observed in an urban forest fragment located in the Amazonian city of Manaus, Brazil. Two hours after the bird defecated, the dung beetle reached the dropping and started manipulating them with its fore- and hindlegs. It did not eat the dung, though. For a clear understanding of the relationships between bird droppings and Amazonian dung beetles, it will be important to perform standardized experiments with a wide variety of native dung and carrion types.

Comparative seasonal analysis of Eri silkworm (Samia ricini Donovan) gut composition: implications for lignocellulose degradation.

Conversion of biomass such as lignocelluloses to an alternative energy source can contribute to sustainable development. Recently, biomass-degrading enzymes are reported to be common resources in insect-microbe interacting systems. Northeast India harbors ample sericigenous insect resources which are exploited for their silk products. Samia ricini Donovan is an economically important poly-phytophagous silkmoth capable of digesting foliage from different plant species, suggesting the versatility of a robust gut system. Here, a gut bacterial profile was determined by 16S rRNA gene characterization across the holometabolous life cycle during the summer and winter seasons, revealing 3 phyla, 13 families, and 22 genera. Comparative analysis among the seasonal gut isolates revealed a high diversity in summer, predominated by the genus Bacillus due to its high occurrence in all developmental stages. Shannon's diversity index demonstrated the second and fourth instars of summer as well as the fifth instar of winter to be relatively better developmental stages for gut bacteria assembly. Bacterial community shifts in concert to host developmental changes were found to be apparent between early instars and late instars in summer, which differed from those of winter. Forty-three and twenty-nine gut bacterial isolates were found to be cellulolytic and xylanolytic enzyme producers, respectively. The present results illustrate the gut microbiota of S. ricini over the seasons and support the holometabolous life cycle effect as the most likely factor shaping the gut bacterial microbiota. These findings may provide leads for the development of new cleaner and environmentally friendly lignocellulose-degrading enzymes.

Flowers of ruderal species are numerous but small, short and low‐rewarding

Weed species are ecological models that recently received considerable attention due to their particular strategies linked to their ruderal‐competitive traits. They are known to have the potential to provide additional floral resources for insects in flower‐poor agroecosystems. However, their floral traits are much more scarcely studied than those of plants found in other habitats, such as grasslands. The aim of this study was to describe the floral phenotype of weeds and to determine to what extent their floral traits match their ecological strategies as described based on leaf traits. We cultivated 19 forb weeds from perennial agroecosystems, previously identified in Mediterranean fields, in a greenhouse for seven months and collected data on 12 floral and five leaf traits. We tested whether these traits covaried and exhibited an ecological strategy at the phenotype scale. We found that in matters of flower production, weed species face a tradeoff: either numerous small, low‐stature flowers with small quantities of pollen and nectar, or few, large, higher‐held flowers with more pollen and nectar. The floral traits were found to reflect Grime's CSR strategies: the weed species producing fewer but costlier flowers belonged to C‐strategy species, whereas those producing more but less costly flowers belonged to species dominated by an R strategy. These findings indicate that the potential of weeds as floral resources for insects is related to their ecological strategies, which are known to be affected by agricultural practices that filter species composition. This implies that, as for the provision of other ecosystem services, weed communities can be managed to select species with floral traits matching the requirements of flower‐visiting insects like pollinators or parasitoid wasps.

Linking changes in individual specialization and population niche of space use across seasons in the great evening bat (Ia io)

BackgroundThe niche breadth of an animal population comprises both within-individual and between-individual variation (individual specialization). Both components can be used to explain changes in population niche breadth, and this has been extensively investigated in dietary niche dimension studies. However, little is known about how changes in food resources or environmental factors across seasons affect changes in individual and population space use within the same population.MethodsIn this study, we used micro-GPS loggers to capture the space use of individuals and of a population of the great evening bat (Ia io) in summer and autumn. We used I. io as a model to investigate how individual spatial niche breadth and spatial individual specialization affect changes in population niche breadth (home range and core area sizes) across seasons. Additionally, we explored the drivers of individual spatial specialization.ResultsWe found that the population home range and the core area of I. io did not increase in autumn when insect resources were reduced. Moreover, I. io showed different specialization strategies in the two seasons: higher spatial individual specialization in summer and lower individual specialization but broader individual niche breadth in autumn. This trade-off may maintain the dynamic stability of the population spatial niche breadth across seasons and facilitate the population response to changes in food resources and environmental factors.ConclusionsLike diet, spatial niche breadth of a population also may be determined by a combination of individual niche breadth and individual specialization. Our work provides new insights into the evolution of niche breadth from the spatial dimension.

Behavioural and Electrophysiological Response of <i>Trichogramma achaea</i> to Oviposition Induced Volatiles in Tomato

A laboratory experiment was conducted at ICAR-National Bureau of Agricultural Insect Resources, Bengaluru to study the behavioural response of Trichogramma achaea towards healthy, conspecifics (Tuta absoluta oviposited on Tuta absoluta infested plants) and heterospecifics (Tuta absoluta oviposited on Liriomyza trifolii infested plants) tomato plants by choice and no-choice parasitization assays and olfactometer studies. Headspace volatiles were collected from tomato plants oviposited by conspecifics, heterospecifics and healthy plants, analysed using gas chromatography-mass spectrometry (GC-MS) where 14, 17 and 8 volatile organic compounds were detected respectively. Electrophysiological compounds and antennal response of T. achaea were identified using gas chromatography-electro-antennographic detector (GC-EAD). EAD active compounds of T. achaea were 3-Hexanol, α-phellandrene, trans-β- ocimene, pentacosane and γ-terpinene.

The Compatibility of Natural Enemies and Botanical for Management of Earias vittella (Fabricius) (Lepidoptera: Nolidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Bhendi Ecosystem

Aims: The current study was conducted to know the compatibility of natural enemies and botanical for management bhendi fruit borers in the bhendi field.
 Study Design: Randomized Complete Block Design (RCBD).
 Place and Duration of Study: Experiment conducted during 2019-20 and 2020-21 at ICAR- National Bureau of Agricultural Insect Resources, Hebbal, Bengaluru, Karnataka, India. 
 Methodology: Two field tests were conducted at the entomological research farm, ICAR-NBAIR Bengaluru, Karnataka, India, to know the compatibility of the natural enemies (Trichogramma chilonis Ishii (Hymenoptera:Trichogrammatidae) , Chelonus blackburni (Cameron) and Bracon brevicornis (Wesmael) (Hymenoptera: Braconidae) and botanical (Neem oil 0.5%) for management of E. vittella and H. armigera on bhendi. Arka Nikita (IIHR) bhendi variety was used for the two trials with different treatments in four replication. The release rates of parasitoids were decided based on the previous parasitic potential studies.
 Results: In the first trial, among the treatments, a combination of T. chilonis + C. blackburni + B. brevicornis and C. blackburni + B. brevicornis recorded the lowest pooled mean larval population reduction over pre-treatment count of E. vittella and were on par with each other, recording 40.19% and 37.27%, respectively followed by T. chilonis + B. brevicornis (31.28%), C. blackburni (30.90%), B. brevicornis (28.64%), Neem oil 0.5% (27.71%), Neem oil 0.5% + B. brevicornis (25.46%) and T. chilonis (25.32%). A similar trend was also observed in combination of T. chilonis + C. blackburni + B. brevicornis and C. blackburni + B. brevicornis against H. armigera, which accounted for 47.19% and 37.22% of reduction over pre-treatment count in the respective treatment combination of parasitoids. The next best treatments were T. chilonis + B. brevicornis (28.21%), C. blackburni (26.56%), B. brevicornis (22.21%), Neem oil 0.5% (20.37%), T. chilonis (17.31%) and Neem oil 0.5% + B. brevicornis (16.07%)
 Conclusion: From this study we recommend that, for bhendi fruit borers management, release of parasitoids like T. chilonis + C. blackburni + B. brevicornis at 50,000+1000+1000 adults/ha, respectively in bhendi field starting from 35 DAS at 15 days’ intervals of duration, two-time release of parasitoids is enough later, they have augmented and reduce the population of fruit borer larvae effectively.

The Parasitic Potential of Bracon brevicornis Wesmael and Chelonus blackburni (Cameron) (Hymenoptera: Braconidae) on the Age of Earias vittella (Fabricius) (Lepidoptera: Nolidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Laboratory Conditions

Aims: The current study was carried out to investigate the parasitic potential of density of two important parasitoids against the age of two important bhendi fruit borer pests.
 Study Design: Completely Random Design (CRD).
 Place and Duration of Study: The study was conducted during 2019-20 and 2020-21 at bio control laboratory of National Bureau of Agricultural Insect Resources (ICAR) Hebbal, Bengaluru (Latitude: 13.097221 Longitude: 77.568291) by adopting standard methodology and materials.
 Methodology: An experiment was designed to examine the effects of parasitoid densities of Bracon brevicornis and Chelonus blackburni on the host age (different instars) larvae of fruit borers two important fruit borers by checking the the percent parasitization. The second, third, and fourth instar larvae of E. vittella were introduced separately at different ratios of Bracon brevicornis parasitoids and host viz., 1:10, 2:10, 3:10, 4:10, and 5:10. Mated female parasitoids were utilised in all cases, and the experiment was carried out in a glass jar of 18 x 12 cm, using the sandwich approach. [1] with four replications. After 24 h, the larvae were observedand the percent parasitization was calculated. The same parasitoids were used for thesecond, third, fourth, and fifth instars larvae of H. armigera. 
 To examine the parasitic potential of C. blackburni, another experiment was conducted with various ratios of its adults and eggs of E. vittella and H. armigera by adopting the procedure of Swamiappan and Balasubramanian [2]. The parasitoid and host eggs were maintained at a ratio of 1:100, 2:100, 3:100, 4:100, and 5:100 with four replications. The observation of percent parasitization was recorded after the egg incubation period.
 Results: The parasitic potential studies showed that the parasitoid host ratio of 5:10 (100%) was the best for E. vittella (II, III and IV instar larvae) with the highest parasitization followed by 4:10 (96.83 %), 3:10 (85.08 %), 2:10 (61.71 %) and least parasitization was observed in 1:10 parasitoid host ratio (52.71 %). Similarly, for H. armigera (II, III, IV and V instar larvae) parasitoid host ratio of 5:10 was recorded the highest parasitization (96.75 %), followed by 4:10 (93.69 %), 3:10 (84.11 %), 2:10 (64.75 %) and least parasitization was observed in 1:10 parasitoid host ratio (45.07 %)
 The parasitic potential of C. blackburni revealed that the 5:100 parasitoid host ratio resulted in the maximum parasitization of 64.75% against E. vittella, followed by 4:100 (60.50%), 3:100 (52.55%), 2:100 (38.27%), and 1:100 (25.60%). Similarly, for H. armigera, parasitization was highest at a parasitoid host ratio of 5:100, followed by 4:100 (64.50%), 3:100 (58.25%), 2:100 (43.45%), and 1:100 (28.50%).
 Conclusion: The parasitoids: host ratio of 5:10 for B. brevicornis and 5:100 for C. blackburni is optimal for managing the bhendi fruit borer complex at the IV instar level.

Seasonal variation of population and individual dietary niche in the avivorous bat, Ia io

The variation in niche breadth can affect how species respond to environmental and resource changes. However, there is still no clear understanding of how seasonal variability in food resources impacts the variation of individual dietary diversity, thereby affecting the dynamics of a population's dietary niche breadth. Optimal foraging theory (OFT) and the niche variation hypothesis (NVH) predict that when food resources are limited, the population niche breadth will widen or narrow due to increased within-individual dietary diversity and individual specialization or reduced within-individual dietary diversity, respectively. Here, we used DNA metabarcoding to examine the composition and seasonality of diets of the avivorous bat Ia io. Furthermore, we investigated how the dietary niches changed among seasons and how the population niche breadth changed when the availability of insect resources was reduced in autumn. We found that there was differentiation in dietary niches among seasons and a low degree of overlap, and the decrease of insect resource availability and the emergence of ecological opportunities of nocturnal migratory birds might drive dietary niche shifts toward birds in I. io. However, the population's dietary niche breadth did not broaden by increasing the within-individual dietary diversity or individual specialization, but rather became narrower by reducing dietary diversity via predation on bird resources that served as an ecological opportunity when insect resources were scarce in autumn. Our findings were consistent with the predictions of OFT, because birds as prey for bats provided extremely different resources from those of insects in size and nutritional value. Our work highlights the importance of size and quality of prey resources along with other factors (i.e., physiological, behavioral, and life-history traits) in dietary niche variation.

Diversity of insect flower visitors of cayenne pepper in agricultural landscapes, Banggai, Central Sulawesi

The existence of semi-natural habitats around agricultural land has the potential to support ecosystem services by providing resources for beneficial insects. The study aimed to analyze the abundance, diversity index, and evenness of the insects visiting cayenne flowers. This research was carried out in cayenne cultivation areas in the Banggai Regency. Sampling locations were divided into two categories: cayenne fields close to and far from forests or semi-natural habitats. Insect collection was carried out from June 2022 to August 2022, in the morning and evening, using insect nets. The results showed that 16 families and 52 cayenne flower-visiting insects were identified. Lasioglossum sp.3, Lasioglossum sp.5, Megachile sp.2, ?Parancistrocerus sp. and Rhynchium sp. have a higher abundance than the others. The highest Shannon and Wiener diversity index was found in cayenne fields in Tolisu Village (H'= 2.491), Mansahang (H'= 2.216), Salodik (H'= 2.145), and the lowest in cayenne fields in Kembang Merta Village (H'= 1.211), Dale-Dale (H'= 1.112 ), and Beringin Jaya (H'= 1.149 ). The highest evenness index (E) was found in the fields in Lembah Makmur Village (E= 0.9721) and Mansahang (E= 0.9172), and the lowest was found in cayenne fields in Petak Village (E= 0.3975) and Lenyek (E= 0.4405). The highest species richness was found in cayenne fields in Tolisu (14 species), Salodik (14 species), and Petak (12 species). Cayenne fields in the three villages are close to semi-natural habitats. Our findings show that agricultural land adjacent to semi-natural habitats has increased the species richness of cayenne flower visitor insects. Thus, semi-natural habitats are critical to sustaining insect communities in agricultural landscapes.

Feeding on an exotic host plant enhances plasma levels of phenoloxidase by modulating feeding efficiency in a specialist insect herbivore.

Background: Exotic plant species represent a novel resource for invertebrates and many herbivorous insects have incorporated exotic plants into their diet. Using a new host plant can have physiological repercussions for these herbivores that may be beneficial or detrimental. In this study, we compared how using an exotic versus native host plant affected the immune system response and feeding efficiency of a specialist lepidopteran, the common buckeye (Junonia coenia: Nymphalidae, Hübner 1822). Materials and Methods: In a lab experiment, larvae were reared on either the exotic host plant, Plantago lanceolata (Plantaginaceae), or the native host plant, Mimulus guttatus (Phrymaceae). Beginning at second instar feeding efficiency data were collected every 2days until fifth instar when immune assays were performed. Immune assays consisted of standing phenoloxidase activity, total phenoloxidase activity, and melanization. Results: Interestingly, we found that all three immune system parameters were higher on the exotic host plant compared to the native host plant. The exotic host plant also supported higher pupal weights, faster development time, greater consumption, and more efficient approximate digestibility. In contrast, the native host plant supported higher efficiency of conversion of ingested and digested food. The relationship between immunity and feeding efficiency was more complex but showed a large positive effect of greater host plant consumption on all immune parameters, particularly for the exotic host plant. While not as strong, the efficiency of conversion of digested food tended to show a negative effect on the three immune parameters. Conclusion: Overall, the exotic host plant proved to be beneficial for this specialist insect with regard to immunity and many of the feeding efficiency parameters and continued use of this host plant is predicted for populations already using it.