Entomologia Experimentalis et Applicata最新文献

The house cricket, Acheta domesticus (Linnaeus) (Orthoptera: Gryllidae) is one of the major insects successfully domesticated for food around the world. However, expensive feed is still a major challenge in the production of the insect, leading to low returns. This study aimed at developing an alternative diet for mass rearing of A. domesticus. We tested five diets, namely commercial chicken mash (CCM; control diet), maize bran supplemented with 50% sunflower seed cake (SFC50), 50% shea seed cake (SBC50), 50% oil palm seed cake (POC50), and 25% maize bran + 25% of each of the oil seed cakes (MSSP25). The experiment was arranged as a randomized unreplicated block design with 50 blocks, each containing one replicate of each diet treatment. Survival of A. domesticus fed on maize bran supplemented with either sunflower seed cake or oil palm seed cake was comparable to that of those fed on the control diet. However, emerging adults on oil seed supplemented diets (SFC50 and POC50) were heavier than their counterparts raised on the control diet. The shortest development time was observed among A. domesticus fed on 50% sunflower seed cake compared to all other diets. Acheta domesticus fed on the control diet was richer in protein, while those reared on maize bran supplemented with either sunflower seed cake or oil palm seed cake contained higher levels of fat, minerals (sodium, calcium, and iron) and polyunsaturated fatty acids (PUFAs). We conclude that supplementation of maize bran with 50% of either sunflower seed cake or oil palm seed cake improves survival and weight gain of A. domesticus and shortens their development time. In addition, these diets modify the nutritional composition of A. domesticus, especially lipids, minerals, and PUFAs. We recommend the use of SFC50 and POC50 as alternative diets to commercial chicken mash in the mass production of A. domesticus.

The black soldier fly (Hermetia illucens L., Diptera: Stratiomyidae) has emerged as a key species in the sustainable protein industry. Whilst genetic variation in performance has been suggested, the extent of heritability and genotype-by-environment (G × E) interactions in this species remains relatively unexplored. This study used a standardised split-brood design and linear mixed effect models to evaluate genetic effects at the between- and within-strain levels across diets as environments. In the first experiment, three strains were tested across three diets to identify strain × diet interactions. Significant interactions were observed for larval weights, development, family viability and protein content, indicating differential adaptability of strains to specific dietary substrates. The second experiment expanded on these results by testing two strains across three diets, but with a larger number of families (n = 23) and individual-level phenotyping of body size using 4018 individuals. Moreover, crude estimates of narrow-sense heritability (h²) were obtained using a full-sibling design. Heritability estimates for larval and prepupal body size were high: h² = 0.67 and 0.78, respectively, although the estimates will be upwardly biased if there is substantial non-additive genetic variation. Together, our results highlight the potential for selective breeding to optimise black soldier fly strains for industrial applications, supporting the growth of this novel industry.

Clanis bilineata tsingtauica Mell, a valued edible insect in China, has seen limited study on its reproductive behaviors despite their importance for mass rearing. This study investigated the effects of mating age, male mating experience, and mating duration on the reproduction and adult longevity of C. bilineata tsingtauica under laboratory conditions. We observed a monandrous mating system for females and a polygynous one for males. The mating rate, oviposition duration, fecundity, and egg hatching rate declined with increasing female mating age. For males, an increase in mating age significantly reduced the mating rate and fecundity, with minimal impact on other parameters. Additionally, increased male mating experience negatively affected fecundity and egg hatching rate, without altering the mating rate, oviposition duration, or adult longevity. Notably, fecundity and egg hatching rate were positively related to mating duration, while oviposition duration was negatively correlated. Our findings indicate that early mating, reduced male mating experience, and extended mating duration enhance the reproductive success of C. bilineata tsingtauica, providing insights for optimizing mass rearing practices.

Heritability measures the proportion of variation in a phenotypic trait within a population attributable to genetic differences among individuals. It also reflects genetic variation that can be passed from one generation to the next, and that can be used to predict the effectiveness of selection on traits involved in enhancing individual performance in genetic breeding programs. In fruit flies, females may select males based on chemical, acoustical, and visual signals as well as physical or morphological characteristics. However, the extent to which genetic variation underlying these traits is passed on to offspring is still largely unknown. Here, we used flies from a genetic sexing strain of Anastrepha ludens (Diptera: Tephritidae), known as Tapachula 7, to determine and compare the probability of mating for males derived from parents where mating interactions were successful vs. those that were not under field cage conditions. Offspring of both groups were propagated in the laboratory, and results showed that males derived from successful parents had a greater probability of mating compared to males derived from parents that were unsuccessful in the field cages. We also estimated the heritability of four morphological traits (pupal weight, thorax length, head width, and wing length) related to male mating success. The morphological characters of pupal weight and thorax length produced relatively low heritability values compared with medium and higher heritability values for head width and wing length, respectively. This study demonstrated that a degree of genetic association exists between reproductive success and some morphological traits associated with mating success in males of the Tapachula-7 strain of A. ludens. The possibility of using these results for improving the sexual performance of sterile males through directed selection is discussed.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive pest for agricultural production. It is associated with the primary symbiont “Candidatus Pantoea carbekii”, which is essential for the host's fitness. In a laboratory rearing, a significant loss of fitness was observed, but the reasons remained unknown. Since bacterial symbionts are known to have an important impact on the fitness of their hosts, we investigated the gut microbiota of laboratory-reared H. halys individuals based on 16S rRNA gene metabarcoding. We analyzed individuals from different generations and compared their microbiota to field-collected individuals. The results showed significant differences between natural and laboratory-reared insects. Especially, the primary symbiont Pantoea, which was the most abundant taxon in the field, was lost and replaced by unclassified Enterobacteriaceae and Yersiniaceae. Our results indicate that changes in the composition of the microbial community of the laboratory-reared H. halys had a significant negative influence on the fitness in the laboratory and highlight the impact of changing conditions to the microbial community of insects with consequences on their fitness.

Genetic improvement through artificial selection holds potential for improving production of the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae). A long-term artificial selection for increased larval body weight is in place for the black soldier fly. To investigate the impact of body weight selection on egg production in this species, four tests were conducted, assessing the phenotypic relationship between pupal body weight, egg clutch weight, number of eggs, and egg size. To measure fecundity, egg clutches were collected from individual females. The egg clutches from the body weight (BW) line, selected for 14, 21, and 32 generations, were compared with those of the base population (BP) line to evaluate the effect of long-term selection for body weight on the reproductive output of the black soldier fly. The maternal pupae weight showed a strong positive correlation (0.73) with egg clutch weight and a moderate positive correlation (0.47) with the number of eggs. The egg clutch weight showed a strong positive correlation (0.79) with the number of eggs and a moderate positive correlation (0.51) with the length of an egg. The BW line showed significantly higher performance over the BP line, with about an 18%–49% increase in egg clutch weight per female, a 24%–30% increase in the number of eggs per clutch, and a 3%–4% increase in the length of an egg. The linear mixed model showed that the selection had significantly increased egg clutch weight over the generations of selection in the BW line. Assessment of phenotypic relationships showed no evidence of reproductive trade-offs with higher body weight in female black soldier flies in this study. This research provides the first empirical evidence of increased fecundity in response to artificial selection for increased larval body weight in the black soldier fly.

The reproductive fitness of parasitoids is dependent on their ability to find optimal hosts for oviposition and nectar/honeydew as a sugar source for survival and reproduction. Learning of ecologically relevant odors helps parasitoids refine their foraging behavior to enhance their reproductive success. However, little is known about how associative learning may help parasitoids optimize their flight behavior while foraging for food and/or hosts. This study compared the inflight behavioral responses of naïve and experienced Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) toward two ecologically relevant, host-related volatile compounds, α-pinene and α-farnesene. Using wind tunnel bioassays, we tested the hypothesis that associative learning of ecologically relevant odors would improve the flight responses of M. croceipes females, resulting in oriented and motivated flight toward the odor sources. A behavioral tracking software, which records the flight behavior of insects in three dimensions, was used to track the inflight behaviors of naïve and experienced parasitoids to ecologically relevant odors (α-pinene and α-farnesene) and compare relevant flight-related parameters (response time, time in upwind flight, speed, angular velocity, and tortuosity). The results showed that associative learning significantly improved the foraging behavior of M. croceipes females. Odor learning resulted in more directly oriented upwind flight toward odor sources compared to naïve females. In addition, comparisons of individual flight parameters revealed that learning enables parasitoids to adapt to specific cues, thereby increasing responsiveness and attractiveness to the learned odor. These findings highlight the adaptive significance of associative learning during foraging and host location strategies in parasitoids.

Sexual size variation in adult holometabolous insects may arise from selective pressures impacting ontogenetic stages associated with diverse habitats and resource use. In addition, scaling relations of these sexually dimorphic traits play an important role in morphological diversification. In mosquitoes, given the sexual differences in feeding strategies, investigations of the ontogeny of sexually dimorphic traits are of particular interest to understanding their reproductive biology and implementing early sex-separating technologies for vector control. However, our current knowledge of the morphological scaling of body parts over development across sexes is centered around a few well-known species of anthropophilic mosquitoes. In general, there is a noticeable gap in our understanding of the developmental biology of mosquitoes with limited medical consequences. One such mosquito is Uranotaenia lowii (Diptera: Culicidae), a species of growing interest due to its unique host use of feeding exclusively on frogs by eavesdropping on their mating calls. This study takes a step forward toward filling this gap by investigating sexual size dimorphism during the ontogeny of Ur. lowii. We examined larval and pupal stages to focus on traits that allow sex identification to evaluate various sex-sorting techniques that provide a foundation for experimental manipulation. We found that sex identification in Ur. lowii is possible during both larval and pupal stages. In the fourth larval instar, thorax length, abdomen length, and total body length differ significantly between the sexes, showing allometric scaling. In the pupal stage, the allometry of the head and thorax to body size remains consistent, as these parts fuse into the cephalothorax. Successful sorting based on cephalothorax length enables highly accurate pupal sex identification. This research sheds light on the biology of Ur. lowii, an understudied mosquito species, and lays the foundation for future studies on the developmental and reproductive biology of frog-biting mosquitoes.

Thermal performance drifts between the egg-parasitoid Telenomus remus and the fall armyworm may threaten the efficacy of biological control under climate change—M. Mubayiwa, H. Machekano, B. M. Mvumi, W. A. Opio, B. Segaiso, F. Chidawanyika, & C. Nyamukondiwa (https://doi.org/10.1111/eea.13557).

The mosquito Aedes aegypti (L.) (Diptera: Culicidae) is a vector of diseases of global importance, such as dengue fever, chikungunya, and Zika. The increasing geographic expansion of this species, as well as its resistance to chemical insecticides, has prompted the search for alternatives to reduce its populations. The sterile insect technique (SIT) is a promising technique that is applied to regulate mosquito vector populations through the release of sterile males. The use of entomopathogens is another promising technique for vector control. In this study, we evaluated the capacity of irradiated Ae. aegypti males to transport spores of the entomopathogenic fungi Beauveria bassiana (Bals.-Criv.) Vuill. (Ascomycota) and Metarhizium anisopliae (Metchn.) Sorokin (Ascomycota) and infect conspecific females. Our results show that irradiated Ae. aegypti males are able to transport and transmit an infection of both entomopathogens to conspecific females. The time to locate a female is more variable for irradiated males, but overall similar to that for nonirradiated males, and independent of fungal infection status. Thus, irradiation does not appear to affect the capacity of males to transmit a fungal infection to conspecific females. A combination of both control strategies, entomopathogens and SIT, is promising for the control of disease-carrying mosquitoes, but future studies of male sexual competitiveness, in the field in addition to the laboratory, are still required.