Bulletin of Entomological Research最新文献

Understanding the blood-feeding patterns of mosquitoes is essential for evaluating their potential as disease vectors, especially in urban areas where mosquitoes coexist with humans, domestic animals and wildlife. This study aimed to bridge a substantial gap in regional knowledge by identifying the blood meal sources of field-collected mosquitoes in domestic and open green environments from two urbanisations of temperate Argentina, the Área Metropolitana de Buenos Aires (AMBA) and Tandil, using molecular techniques. Female mosquitoes were collected from November 2019 to March 2020 and April–May 2021. A bipartite network analysis was performed for each environment and urbanisation. A total of 103 blood meals from Aedes (2 species) and Culex (7 species) were identified. Among these, five mammal and 18 bird species were recognised as hosts. Aedes mosquitoes exclusively fed on mammals, while Culex mosquitoes exhibited a broader host range including both birds and mammals. In AMBA, the open green environments were composed by more mosquito species than the domestic environments, while both presented similar numbers of vertebrate species. In contrast, in open green environments from Tandil only blood-fed Aedes albifasciatus were collected. For open green environments of AMBA and domestic environments of Tandil, results suggested some degree of host selection. For the three main vectors of diseases in the region, Aedes aegypti, Ae. albifasciatus and Culex pipiens molestus, we present the first molecular evidence of human blood meals in South America. Epidemiological significance of the present findings is discussed.

Mutualism between ants and honeydew-producing hemipterans is a highly successful evolutionary innovation that attains the status of ecological keystone across many terrestrial ecosystems, involving a multitude of actors through direct or cascading effects. In these relationships, ants often protect their hemipteran partners against their arthropod natural enemies, sometimes interfering with the biological control of pest species. However, the dynamics of these interactions are highly variable based on the specific identity of all the actors involved, and baseline data remain scarce. We performed a field experiment exposing colonies of the walnut aphid Panaphis juglandis attended by five European ant species (Camponotus piceus, Ca. vagus, Crematogaster scutellaris, Dolichoderus quadripunctatus, Lasius emarginatus) to a native and an exotic lady beetle (Adalia bipunctata and Harmonia axyridis), documenting the behavioural interactions between these insects and the performance of ants in the protection of the aphids. Our results reveal a significant behavioural diversity among the ant species involved, with D. quadripunctatus and L. emarginatus being the most aggressive and having the best performance as aphid defenders, and Ca. piceus being least effective and often fleeing away. Cr. scutellaris displayed a rare rescue behaviour attempting to pull away the aphids that the lady beetles grabbed. On the other hand, behavioural responses to A. bipunctata and H. axyridis were similar. Further investigations are needed to understand the eco-ethological implications of these differences, while a better understanding of ant behavioural diversity may help refine biological control strategies.

Effective early detection, monitoring and management methods are critical for reducing the impacts of insect pests in agriculture and forestry. Combining host plant volatiles with sex pheromones could enhance trapping methodologies, whilst the use of non-host volatiles could improve the effectiveness of pest management through repellency effects. In this meta-analysis approach, we analysed 51 studies that used electroantennograms (EAG), wind tunnels and/or field traps to evaluate the antennal and behavioural responses of Lepidoptera to sex pheromones combined with attractant or repellent plant volatiles. Proposed attractant plant volatiles had a positive association with female Lepidoptera responses to sex pheromone, but effects on males were highly variable, with unexpected repellency reported in some studies. Proposed repellent plant volatiles were significantly or near-significantly negatively associated with male attraction to sex pheromones but were scarcely studied. Sub-group analysis identified that male responses to sex pheromone were reduced when the dose of attractant plant volatile relative to sex pheromone was increased. Green-leaf volatiles were associated with the strongest positive effects for males in field traps. Multiple-compound attractant plant volatile blends were less effective than single compounds in field studies. Our analysis demonstrates, (i) the potential value of combining host plant volatiles with sex pheromones to capture females rather than only males, (ii) the importance of identifying appropriate host plant volatiles and optimal relative doses, and (iii) the potential for non-host plant volatile use in pest management strategies.

The egg parasitoid Cleruchoides noackae Lin & Huber, 2007 (Hymenoptera: Mymaridae) is originated from Australia and the main biological control agent of Thaumastocoris peregrinus Carpenter & Dellapé, 2006 (Hemiptera: Thaumastocoridae) on Eucalyptus L'Hér (Myrtaceae). Companies that grow Eucalyptus are in need of a mass rearing protocol to increase the number of individuals produced and improve the quality of this parasitoid. The aim of this study was to define a protocol for mass rearing C. noackae in T. peregrinus eggs, based in the evaluations of the key biological attributes of this parasitoid in the parental and F1 generations, after the cold storage of the parasitised host eggs. Two methods were tested as C. noackae rearing protocols. In the first, parasitised eggs of T. peregrinus by C. noackae were cold stored for 7 days after being left in a climatic chamber at 24 ± 2°C, 60 ± 10% RH and a photoperiod of 12:12 (light:dark) h (standard environmental conditions) for 3, 6, 9 or 12 days. In the second, T. peregrinus eggs parasitised by C. noackae were maintained in a climatic chamber under standard environmental conditions for 6 days, after which these eggs were cold-stored for 0 (control), 7, 14 or 21 days. Parasitism (%), and the development period (parasitism to adult) and female proportion (%) of C. noackae were evaluated. Based on the results (parental generation: parasitism, around 45%; F1 generation: parasitism, around 55%; development period, around 16 days; female proportion, around 60%), eggs should be stored at 5°C on the sixth day after parasitism by C. noackae and maintained at this temperature for 7 days. The cold storage of T. peregrinus eggs, after parasitism, can be included in the mass rearing protocols of the parasitoid C. noackae.

Periplaneta americana, one of the most widely distributed insects all over the world, can survive and reproduce in harsh environment which may be closely related to the critical roles of intestinal microorganisms in its multiple physiological functions. However, the composition and structure of gut microbiota throughout different life stages and its effects on the strong resilient and environmental adaptability of P. americana remain unclear. In this study, the gut microbiota across life stages including ootheca (embryos), nymph and adult of P. americana were investigated by 16S rRNA high-throughput sequencing. Multivariate statistical analysis showed the richness and diversity of bacterial communities were significantly different among ootheca, nymph and adult stage of P. americana. Taxonomic analysis showed Blattabacterium was the dominant genus in bacterial community of ootheca while the nutrient absorption-related genera including Christensenellaceae and Ruminococcaceae showed high relative abundance in nymph samples. Moreover, functional prediction analysis showed the metabolic categories in ootheca might have more influence on the basic life activities of the host than improved production and viability, while it was more associated to the society activities, reproduction and development of host in nymph and adult. It was suggested that the gut microbiota in each life stage might meet the requirements for environmental adaptability and survival of P. americana via transforming the composition and structure with specific metabolic capabilities. Overall, these results provided a novel sight to better understand the strong vitality and adaptability throughout life stages of P. americana.

The ecological function played by the coprophagous insects is an important issue in livestock production contexts. The role of this fauna, specially dung beetles, provides benefits to both rangelands and production performance. This interaction has been studied and reported in many scientific articles, in very different places and with diverse production contexts. However, a comprehensive review of the relationship between coprophagous insects and livestock production is still lacking. We reviewed the research studies on this topic during the past five decades, with a focus in Scarabaeidae taxon and livestock production, in order to identify further research priorities. We analysed 435 research articles. The main results were: (I) studies were mostly located in temperate broadleaf forest biome, whereas arid environments were less studied; (II) Production practices impacts category was the most studied, for which the effects produced by antiparasitic products on the coprophagous insects (n = 93; 21% of total revised articles) was the topics with major number of articles. Followed was Biology category (n = 69; 16%), then in Ecosystem function category the most frequent studies were on dung removal (n = 40; 9%), whereas in the Ecosystem Services category the most frequent studies were on biological control (n = 28; 6%); (III) Australia, Mexico, Brazil, and United States were the countries with most research articles. We identified some knowledge gaps on relevant ecological functions of this fauna, in relation to benefits to livestock production. There is a need for future research on nutrient cycling, bioturbation, effects on primary production and vegetation diversity.

The silkworm Bombyx mori (Lepidoptera: Bombycidae) is a lepidopteran model insect of great economic importance. The parasitoid Exorista sorbillans (Diptera, Tachinidae) is the major pest of B. mori and also a promising candidate for biological control. However, the molecular interactions between hosts and dipteran parasitoids have only partially been studied. Gene expression analysis by reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR) is indispensable to characterise their interactions. Accurate normalisation of RT-qPCR-based gene expression requires the use of reference genes that are constantly expressed irrespective of experimental conditions. In this study, the expression stability of 13 traditionally used reference genes was estimated by five statistical algorithms (ΔCt, geNorm, Normfinder, BestKeeper, and RefFinder) to determine the best reference genes for gene expression studies in different tissues of B. mori under E. sorbillans parasitism. Specifically, TATA-box-binding protein was the best reference gene in epidermis and testis, while elongation factor 1α was the most stable gene in prothoracic gland and midgut. Elongation factor 1γ, ribosomal protein L3, actin A1, ribosomal protein L40, glyceraldehyde-3-phosphate dehydrogenase and eukaryotic translation initiation factor 4A were the most suitable genes in head, silk gland, fat body, haemolymph, Malpighian tubule and ovary, respectively. Our study offers a set of suitable reference genes for gene expression normalisation in B. mori under the parasitic stress of E. sorbillans, which will benefit the in-depth exploration of host-dipteran parasitoid interactions, and also provide insights for further improvements of B. mori resistance against parasitoids and biocontrol efficacy of dipteran parasitoids.

Fruit fly infestation is one of the main obstacles to the exportation of fresh agricultural produce. Films of mineral particles and biomaterials have the potential to protect fruits against tephritid fruit fly infestation. The present study evaluated the effects of particle films on the tritrophic interactions of grape (Vitis vinifera L.), the fruit fly Ceratitis capitata (Wiedemann) and the parasitoid Diachasmimorpha longicaudata (Ashmead) under semi-field conditions. Grapes were biometrically characterised (i.e. colour, firmness, mass, length and diameter), treated with mineral particles, biomaterials or distilled water (control), and then used in oviposition and parasitism bioassays. In the oviposition bioassay, the treated grapes were exposed to 50 C. capitata pairs in field cages, and after 48 h, the punctures and eggs on each fruit were counted. In the parasitism bioassay, treated grapes were artificially infested with third-instar C. capitata larvae (two per fruit), exposed (2 h) to 50 D. longicaudata pairs in field cages to determine parasitism index, larval and pupal viabilities and number of flies and parasitoids emerged. Treatment with the mineral film affected fruit colour and reduced C. capitata oviposition but failed to significantly affect the parasitism capacity of D. longicaudata. The ability of the parasitoid to locate and parasitise C. capitata larvae in kaolin-coated fruits suggests that kaolin films could be used in conjunction with biological agents to control fruit flies.