Aphis craccivora Koch (Hemiptera: Aphididae) or cowpea aphid is a polyphagous insect pest that feeds on a variety of leguminous plants. We determined the contribution of host-associated genetic differentiation on population structure using the sequence data generated from analysis of mitochondrial cytochrome b oxidase (Cytb) and nuclear elongation factor-1 alpha (EF1-alpha) of A. craccivora collected from cultivated yardlong bean [Vigna unguiculata (L.) Walp. ssp. sesquipedalis (L.) H. Ohashi.] (Fabales: Fabaceae) and winged bean [Psophocarpus tetragonolobus (L.) D.C.] (Fabales: Fabaceae). Phylogenetic and haplotype network analyses revealed no evidence of strong host plant or geographical clustering in both the mitochondrial and nuclear gene dataset. A moderate, low-magnitude genetic distance (F_ST) between host plants and geographical localities was found in this study. An analysis of molecular variance (AMOVA) revealed that host plant and geography do not influence the structure of genetic variation in A. craccivora populations. Genetic variation between host plants at a location and host plants among locations demonstrated no consistent result for population subdivision of A. craccivora. These results suggest that geographical location and host plants do not significantly influence the genetic structure of A. craccivora, and this might be due to their high reproductive (parthenogenesis) ability and high migration (airborne) between host plants and regions of the country.

The population dynamics of freshwater organisms are expected to be related to the connectivity among comparable streams, ponds, or rivers in a patchy habitat. Here, we investigated the population dynamics of the giant water bug, Belostoma angustumLauck 1964 (Hemiptera: Belostomatidae), in a fine-scale spatial sampling, and evaluated which gene flow model previously described for freshwater organisms could explain the genetic–morphological variation in this species. For these purposes, we evaluated genetic and morphological variations, as well as the demographic history of this freshwater insect. Our genetic analyses showed a lack of geographical structure within B. angustum populations across the evaluated range, concordant with widespread gene flow model. Our findings of the demographic history of B. angustum suggest recent and rapid expansion beginning during the late Pleistocene after the Last Glacial Maximum. Likewise, we did not find geographically structured morphological variation in B. angustum, except for body size. The lack of structure of genetic–morphological variation in B. angustum could be explained by a stepping ponds system resulting in the widespread gene flow detected among populations of this species. The warmer and wetter climatic conditions after the last glacial period may have favored the demographic expansion of B. angustum populations due to the increasing of potential freshwater habitats and food resources. This favorable habitat probably allowed the stepping ponds dispersal mode resulting in the verified geographically unstructured genetic–morphological variation.

Cotesia chilonis (Munakata) is an endoparasitoid wasp of Chilo suppressalis Walker (Lepidoptera: Pyralidea) larvae. Little is known regarding the tolerance of C. chilonis after cold acclimation at different temperatures. In this study, we investigated mortality and the molecular basis of temperature tolerance in C. chilonis reared under normal conditions (27°C) and after cold acclimation at 4°C for 5 d. We evaluated the relative expression of five genes encoding heat shock proteins (HSPs) in C. chilonis by RT-qPCR after cold acclimation and exposure to temperature stress.The results demonstrated that cold acclimation could significantly enhance the survival of C. chilonis adults under high temperatures, and expression of the five C. chilonis HSP genes had distinctly different expression patterns in response to temperatures. Cchsp40 and Cchsp90 had similar expression pattern that upregulated significantly at –12 and 39°C. Cchsp70 could be induced by high and low temperatures, whereas Cchsp60 and Cchsc70 showed no significant difference in expression when exposed to thermal stress. This study provides important biological information that may help extend the shelf life of C. chilonis, which is an important consideration in the use of this wasp as a biological control agent.

Although poor nutrition is cited as one of the crucial factors in global pollinator decline, the requirements and role of several important nutrients (especially micronutrients) in honey bees are not well understood. Micronutrients, viz. phytosterols, play a physiologically vital role in insects as precursors of important molting hormones and building blocks of cellular membranes. There is a gap in comprehensive understanding of the impacts of dietary sterols on honey bee physiology. In the present study, we investigated the role of 24-methylenecholesterol—a key phytosterol—in honey bee nutritional physiology. Artificial diets with varying concentrations of 24-methylenecholesterol (0%, 0.1%. 0.25%, 0.5%, 0.75%, and 1% dry diet weight) were formulated and fed to honey bees in a laboratory cage experiment. Survival, diet consumption, head protein content, and abdominal lipid contents were significantly higher in dietary sterol-supplemented bees. Our findings provide additional insights regarding the role of this important sterol in honey bee nutritional physiology.The insights gleaned from this study could also advance the understanding of sterol metabolism and regulation in other bee species that are dependent on pollen for sterols, and assist in formulation of a more complete artificial diet for honey bees (Apis mellifera Linnaeus, 1758) (Hymenoptera: Apidae).

The white maguey worm, Aegiale hesperiaris (Walker, 1856), is a gastronomic delicacy in Mexico, with high economic value. Aegiale hesperiaris is generally associated with the plant Agave salmiana Otto ex Salm-Dyck (Asparagales: Asparagaceae). However, lack of information about Ae. hesperiaris means that it is often confused with morphologically similar species such as Agathymus remingtoni D. Stallings & Thurner (Lepidoptera: Hesperiidae), a species generally found on Agave lechuguilla Torrey (Asparagales: Asparagaceae). Harvestings are made from all Agave L. (Asparagales: Asparagaceae) species on the assumption that all larvae will be Ae. hesperiaris. This has led to the belief that Ae. hesperiaris may have extended its diet breadth range and is actually infesting other Agave species. We collected larvae from A. lechuguilla and A. salmiana plants, in Hidalgo state, Mexico, and incubated them at 26°C, 50% RH and 12:12 light regime until adult emergence; adults were examined using morphological (male genitalia and wing patterns) and molecular techniques (partial COI sequences) to provide the data necessary for accurate species identification and allocation to host plant. Both species were successfully separated and identified as Ae. herperiaris feeding on A. salmiana and Ag. remingtoni feeding on A. lechuguilla, and a detailed description of the larval developmental stages and feeding behavior described. These results will facilitate the accurate identification of these two species in future studies.

Female authors and reviewers are significantly underrepresented in entomology journals, consistent with many other STEM journals. During the years 2001 through 2017, women published significantly fewer first-author and single-author articles in five ESA journals and the Annual Review of Entomology. Female reviewers are also significantly outnumbered by male reviewers in ESA journals. Results show that in general, female first author and reviewer proportions are rising over time but progress is slow, about 1% yearly for both authors and reviewers. There are a greater number of female authors than female reviewers, but proportions are significantly related to each other, suggesting that female authors and reviewers reinforce the presence of each other. Potential contributing factors for these results include peer review, funding levels for research, time available for research, and women's self-confidence and collaboration with other scientists.

We examined the adult phase of the Chinese praying mantid, Tenodera aridifolia sinensis (Saussure) (Mantodea: Mantidae) at the end of five growing seasons spanning two decades (1999–2018) in a successional old field. Sex ratio, which is generally male-biased by the time all members of a cohort are adults, exhibited a steady decline in proportion of males and eventual reversal by 2016, even though the calendar time of the study did not vary among years. Increasing length and warmth of the growing season resulted in earlier maturation, so we were seeing later portions of the adult phase at the same calendar time over successive years. This result is consistent with the earlier-published hypothesis that global warming can reduce fitness by warming and extending the growing season: earlier maturation results in earlier oviposition, which in turn causes eggs to hatch before onset of winter, thereby dying before egg diapause can occur.This may push the latitudinal distribution of this, and of other univoltine semelparous insects, farther north as the climate continues to warm. Reproductive output for the population, measured as total number of eggs produced by a cohort, peaked in 2004 at 8,514 and then fell to 226 by 2018, as did estimated numbers of adults. This decline was probably due to shrinkage of the open field area where prey were more abundant, by more than 2/3 as cedar trees replaced herbaceous vegetation during plant secondary succession.This is consistent with the hypothesis that succession limits the residence time in a habitat for these mantids.

There is noticeable variation in male mate-seeking behavior among species of Brassolini butterflies. Males of Opsiphanes Doubleday and Caligo Hübner (Lepidoptera, Nymphalidae) species perform crepuscular displays along forest edges and in light gaps. While male Opsiphanes perform aerial displays, Caligo males perch and wait for receptive females. A comparison of five species of each genus suggests that male display behavior is associated with, and has likely influenced the evolution of their wing attributes and body design. Opsiphanes males have higher wing aspect ratio and more distal centroid position than congeneric females, suggesting that the energetic demands of aerial displays led to sexual dimorphism in wing morphology. In contrast, male and female Caligo generally showed similar wing morphology, which possibly results from the lower energy expenditure of perching behavior when compared with active flight. Likely due to a genetic correlation between sexes, female Opsiphanes and Caligo are more similar in wing morphology and body design to their congeneric males than to each other. Based on our analyses, we make predictions about reproductive behavior for four species in which male mating displays are unknown.

The flour beetles Tribolium castaneum (Herbst) and Tribolium confusum (du Val) are model organisms for studying the effects of intra- and interspecific competition. Both species are known to compete directly through egg cannibalism and indirectly through the density-dependent release of allelopathic chemicals.To better characterize these indirect interactions, recent work has focused on quantifying the per-capita effects of intraspecific chemical competition. However, the effects of interspecific chemical competition in this system have not previously been estimated. We used experimental microcosms to examine how interspecific chemical secretions affected the reproductive activity and development time of laboratory populations of T. castaneum and T. confusum. We created replicated habitats containing flour medium that had been occupied and chemically ‘conditioned’ by one of the two beetle species across a range of densities, then examined how beetles of the other species responded in terms of the number of eggs laid by females and, separately, the development time of offspring. We found that T. castaneum fecundity was reduced when beetles experienced flour conditioned by T. confusum. In contrast, fecundity of T. confusum was largely unaffected by flour conditioned by T. castaneum. Additionally, we found that interspecific conditioning decreased development times for beetles of both species, particularly the development of larvae to pupae. Our results indicate that interspecific chemical competition impacts the life history of Tribolium species and suggests that models incorporating chemical competition may more accurately describe the biology of flour beetle communities.