Entomologia Experimentalis et Applicata最新文献

Agroecosystems are frequently disrupted by aggressive management practices. In the case of alfalfa, regular cutting events during the season cause abrupt resource depletion, often leading to the spillover of insects into nearby areas. In this study, we assessed whether alfalfa populations of the polyphagous aphid Aphis craccivora Koch (Hemiptera: Aphididae) can utilize black locust and vetch, two common plants found near alfalfa fields, as alternative hosts following cutting events. We also determined the ability of these plants to act as A. craccivora reservoirs for the recolonization of alfalfa stands once regrowth occurs. To address these questions, we conducted host specialization trials involving host shifting in three different A. craccivora populations collected from alfalfa, black locust, and vetch. We recorded a comprehensive set of life history parameters using the two-sex life table procedure. The degree of host specialization varied among different A. craccivora populations. The alfalfa-origin population showed relatively good performance when shifted to either black locust or vetch, suggesting these plants may act as refuges for population rebuilding after cutting events, until alfalfa regrowth allows for recolonization. In contrast, populations originating from black locust or vetch performed very poorly on alfalfa, suggesting the colonization of alfalfa fields by these populations is unlikely. The mechanisms underlying host specialization in different A. craccivora populations and the observed differences in dietary diversity are discussed. This study provides valuable insights into the ecology of this insect in the most significant Spanish alfalfa-producing region.

Populations of pest insects can differ in their responses to resistant plants, which can significantly impact the durability of plant resistance. Differential fitness of populations of thrips Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) has been reported previously and other thrips species, such as Thrips tabaci Lindeman (Thysanoptera: Thripidae) and Thrips parvispinus Karny (Thysanoptera: Thripidae), may not be affected by plant resistance. In this study, we assessed the performance of F. occidentalis populations collected in the Netherlands on various Chrysanthemum accessions (Asteraceae) and characterized the genetic diversity of these populations. Analysis of the mitochondrial CO1 gene revealed five distinct haplotypes among F. occidentalis individuals from different populations, belonging to both the glasshouse and lupin strains. Significant differences in the development of thrips larvae (from the L1 to L2 stage) across five F. occidentalis populations on the five evaluated Chrysanthemum accessions were found. Two accessions, Chrysanthemum seticuspe (Maxim.) Hand.-Mazz. PB-MB133 and Chrysanthemum x morifolium Ramat. cv. Penny Lane, were consistently resistant, exhibiting low larval development for all F. occidentalis populations. We also examined the resistance of the Chrysanthemum accessions against T. tabaci and T. parvispinus. When comparing thrips larval performance on various Chrysanthemum accessions for the three thrips species, we found significant effects of plant accession, thrips species and their interactions on larval development. Penny Lane exhibited suppression of larval development for only F. occidentalis, whereas C. seticuspe PB-MB133 suppressed larval development of all three thrips species tested. Interestingly, C. seticuspe PB-MB132, previously identified as susceptible to F. occidentalis, suppressed T. parvispinus development, indicating that in C. seticuspe multiple mechanisms of resistance might be present. In conclusion, our findings demonstrate that thrips populations infesting Chrysanthemum differ in virulence, highlighting the importance of screening for resistance with multiple populations. Moreover, our study identified Chrysanthemum accessions exhibiting resistance against multiple thrips species.

Host plant quality is recognized to have a significant impact on the performance of herbivorous insects. Nitrogen, a fundamental element, plays a crucial role in plant life cycles, serving as a limiting resource for both plants and herbivores. Despite nitrogen-fertilized plants generally exhibiting enhanced nutritional content, responses to nitrogen variations remain non-uniform, depending on specific insect feeding guilds and the nature of herbivore–plant interactions. In the context of modern agriculture, fertilizers are essential for maintaining soil fertility and crop productivity. Focusing on corn, a fundamental crop in the American continent, heightened fertilizer input has significantly increased yields. However, the intricate relationship between pest behavior and fertilization practices necessitates elucidation. This study aimed to examine the effects of varying levels of nitrogen fertilization on the survivorship, developmental time, and performance of the corn leafhopper Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae), a major maize pest and vector of the corn stunt disease. Bioassays were carried out under controlled conditions, and the vector was fed on maize plants subjected to three fertilization levels (100, 200, and 300 ppm). The results indicate that higher levels of nitrogen fertilization doubled the survival rate of nymphs and accelerated their development into adults. Additionally, adults that received high levels of nitrogen fertilization exhibited twice the longevity and fecundity. The reported findings could contribute to predicting the population dynamics of this crop pest and would enable rational decision-making when intervening for D. maidis control.

This study investigates the impact of light intensity on the physical defenses of sugar maple (Acer saccharum Marshall [Sapindaceae]) saplings and how these defenses affect interactions with insect herbivores. The study conducted at the Kenauk Nature Reserve in Quebec involved 12 sites representing both shaded and sunlit environments. Leaf traits, including thickness, specific leaf area (SLA), water content, and toughness, were measured from 216 leaves collected in 2021 and 40 in 2022. To explore herbivore interactions, we used two Erebid caterpillar species, the invasive spongy moth (Lymantria dispar (Linnaeus) [Lepidoptera: Erebidae]) and the native white-marked tussock moth (Orgyia leucostigma (J. E. Smith) [Lepidoptera: Erebidae]), in controlled bioassays that assessed caterpillar feeding preference and performance. The results revealed that sunlit leaves were significantly thicker and had lower SLA compared with shaded leaves across both years. While water content was lower in sunlit leaves in 2021, it showed no significant difference in 2022. Leaf toughness, measured only in 2022, did not significantly differ between sunlit and shaded leaves. Caterpillar feeding preference tests indicated that white-marked tussock moth caterpillars consumed more sunlit leaves, showing a significant preference for them. However, spongy moth caterpillars did not exhibit a significant preference. In terms of performance, white-marked tussock moth caterpillars had a higher survival rate and larger pupal mass on sunlit saplings in 2021. However, no significant differences were observed in laboratory feeding initiation assays with first-instar caterpillars in 2022. These findings suggest that trees' investment in sun leaves to maximize photosynthesis is not necessarily followed by increased defense against herbivory. This research contributes to our understanding of how environmental factors like light can shape plant defense strategies and impact insect herbivore dynamics in temperate forests.

Production insects are cultured by humans to yield an agent or product of (commercial) interest. Four main categories are as follows: insects produced for biological pest control, for sterile insect technique, for human food and animal feed, and for technical products and services. Trait selection in production insects refers to the choice of traits that are important for the insect producer, or it refers to the improvement of a production trait through insect breeding. This special journal issue comprises a series of articles on trait selection, dealing with the outcomes of selection programmes as well as the choice of traits to select. Although the traits of interest occasionally differ substantially between production areas, methodologies for trait improvement may overlap and results of studies will be informative across fields. In this introduction, we first discuss the main aspects of trait selection, and we briefly summarize all contributions to this special issue. Then we systematically review the literature on effect sizes and correlated responses of artificial selection for trait improvement in production insects. We finish with several general conclusions and recommendations for future research, based on our literature review as well as the articles in this journal issue.

The traditional methods of sourcing and semi-domesticating the African palm weevil Rhynchophorus phoenicis Fabricius (Coleoptera: Curculionidae) larvae persist among the inhabitants of Ghana. However, these methods produce only a small proportion of the market demand for the larvae in Ghana. A containerized system of producing larvae has been found to facilitate production for socioeconomic purposes, thereby enhancing the sustainable utilization of the larvae all year round. We evaluated the life history parameters of R. phoenicis on three different rearing protocols that used different agricultural by-products, container types, and number of adult pairs for production. The different protocols were laid out using the Completely Randomized Design (CRD) with 10 replications. The fecundity of the adults differed significantly among the protocols. The highest fecundity was recorded on Protocol 2 (145.50 ± 16.55), followed by control (98.50 ± 12.05), Protocol 3 (84.50 ± 9.50), and Protocol 1 (45.00 ± 11.58). Protocol 2 recorded the highest larval survival rate, followed by Protocols 1, control, and 3. Among the rearing protocols, the highest intrinsic rate of natural increase (rm) (days) and net reproductive rate (Ro) were observed in Protocol 2. The lowest mean generational time (T) was recorded on Protocol 2 (76 days) while the highest (92 days) was recorded on Protocol 3. Our findings showed that Protocol 2 supports fecundity, larval development, cocooning formation, and adult emergence. The adoption of Protocol 2 by smallholder insect farmers can contribute to the development of future commercial rearing systems for R. phoenicis larvae.

The zoophytophagous predator Dicyphus hesperus Knight (Hemiptera: Miridae) is effective in the biological control of whiteflies in greenhouses, but it can also cause damage to fruits and plants. Artificial selection on foraging behavior allows the development of more zoophagous lines that have the potential to be both more effective and less likely to cause damage. Moreover, highly zoophagous lines could affect other biological control agents through increased intraguild predation or competition. This study tests the biological control efficacy against tobacco whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and damage by highly and lowly zoophagous lines of D. hesperus in tomato greenhouses. The effect of these lines on Encarsia formosa Gahan (Hymenoptera: Aphelinidae) parasitoid wasp populations was also tested. In cage tests, we introduced D. hesperus from lowly or highly zoophagous and non-selected lines. In half of the cage, E. formosa was introduced. The ability of predators and parasitoids to reduce B. tabaci populations was monitored for 12 weeks. Tomatoes produced were harvested and graded according to damage by D. hesperus. Highly zoophagous lines had a rapid and lasting impact on pest populations. Lowly zoophagous lines take longer to achieve the same level of pest control as highly zoophagous lines. Introductions of E. formosa also reduce populations, but without interacting with D. hesperus. Dicyphus hesperus did not affect E. formosa abundance. Lowly zoophagous lines generated higher proportions of damage. The results show that artificial selection based on zoophagy produces more efficient and less damaging lines in the greenhouse tomato crop. Over time, lines with low zoophagy compensated for low individual efficiency by increasing their numbers. Highly zoophagous lines are compatible with parasitoid wasps, which were little affected by D. hesperus.

Understanding the molecular mechanisms used by phytophagous insects to survive and feed on new hosts is key to explaining their mechanisms of range expansion and diversification. However, only a few Neotropical biological models have been used to understand these mechanisms. In this study, we investigated the differences in gene expression of the Neotropical phytophagous insect Anastrepha obliqua Macquart (Diptera: Tephritidae), the West Indian Fruit Fly, when feeding on three different host plant species under sympatric and synchronous conditions. Third-instar larvae of A. obliqua infesting red mombin (Spondias purpurea L.), mango (Mangifera indica L.), and carambola (Averrhoa carambola L.) were collected in two localities in southwestern Colombia. After assembling a de novo transcriptome, differences in gene expression between larvae infesting the three host species were established using a batch effect design, controlling the variability introduced by location. Sixty-four differentially expressed unigenes were identified among flies infesting the different hosts, with the greatest number of genes differentially expressed between red mombin and carambola. Digestive genes, such as alpha-amylases and serine proteases, were upregulated in larvae from red mombin compared with mango (six genes) and carambola (four genes), suggesting the response of A. obliqua to the nutritional composition in red mombin. Also, two genes related to immune system responses, glutactin and acidic phospholipase A2, were upregulated in mango compared to carambola. Notably, genes annotated as transposable elements (TEs) were consistently upregulated in larvae infesting carambola and mango compared to larvae infesting red mombin. This may suggest the activation of these TEs in acclimation or adaptation to new hosts. Based on our results, the main categories of differentially expressed genes in A. obliqua were serine proteases, detoxification proteins, and proteins associated with the regulation of gene expression. These results support the potential of A. obliqua to adapt to host plants and its qualification as a generalist species.

Aedes aegypti (L.) and Aedes albopictus (Skuse) are important vectors that transmit arboviruses such as Dengue virus (DENV), Yellow fever virus (YFV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Focusing on the unique characteristics of their eggs to withstand dry conditions, this study aimed to elucidate the viability of dry-stored eggs and the subsequent morphometric changes in larvae and adult mosquitoes upon rehydration. Experiments were carried out using ovitrap-collected eggs, which were reared in the laboratory until adult emergence. The resulting mosquitoes were fed on cattle blood and sugar solution and allowed to lay eggs on the paper strips, which were air-dried and stored for 6 months. The viability of these eggs was tested monthly. The head length and total length of fourth-instar larvae and head, thorax, abdomen, wing length, wing width, and total length of adults were measured, including the days needed for adult emergence. The results imply that the prolonging of the egg storage period led to a decline in viability, delayed emergence of adults, and a negative impact on the morphometrics of fourth-instar larvae in both Ae. aegypti and Ae. albopictus. Nonetheless, the morphometrics of the adults did not exhibit any significant differences compared to those of fresh eggs.

With growing concerns over agricultural waste management and sustainable protein sources, insect farming has emerged as a promising waste valorization strategy. However, the effects of agricultural waste-based diets on the growth, gut microbiota, and flavor quality of edible insects remain unclear. This study investigates how different agricultural waste-based feeds influence the biological and flavor characteristics of Zophobas morio Fabricius (Coleoptera: Tenebrionidae), providing insights into its potential applications in waste recycling and edible insect production. Over a 32-day feeding period, Z. morio were fed wheat bran (WB), edible mushroom sticks (EMS), or apple pomace (AP). Growth performance, gut microbiota, and volatile organic compounds (VOCs) were analyzed using 16S rRNA sequencing and gas chromatography-ion mobility spectrometry (GC-IMS). WB-fed Z. morio exhibited the highest weight gain, with increased Lactobacillus and Lactococcus, while EMS increased Spiroplasma without improving growth. AP maintained survival but reduced weight gain while enriching Chryseobacterium and Kosakonia. Gut microbiota influenced the VOC profile, with Lactobacillus and Lactococcus promoting the formation of esters and ketones, Chryseobacterium enhancing sweet and fruity volatiles, and Spiroplasma potentially reducing the production of alcohols and sulfur-containing compounds. These findings provide a basis for optimizing Z. morio as a sustainable solution for agricultural waste recycling and enhancing its potential as an edible protein source.