Annals of The Entomological Society of America最新文献

Ideally, biodiversity surveys would sample insect assemblages randomly and without taxonomic bias, yet most protocols still prioritize conspicuous, charismatic, or economically important taxa (eg pollinators). Consequently, Diptera, one of the most species-rich and ecologically important insect orders, remain largely overlooked, with only a few families like Syrphidae routinely included in biodiversity assessments. To address this imbalance, here we tested a protocol designed to better capture the diversity of non-charismatic dipteran groups by comparing hand-netting and pan traps and by overcoming taxonomic impediments with cost-efficient DNA "megabarcoding" using non-destructive DNA extraction and third-generation sequencing. We applied it to brachyceran fly (Diptera: Brachycera) assemblages across four Mediterranean coastal habitats, key for coastal protection and tourism yet poorly documented. We clustered 13,877 cytochrome c oxidase subunit I barcodes into 823 molecular operational taxonomic units (MOTUs) at a 2% distance threshold, more than 10% of all Diptera species recorded for Italy. MOTUs were assigned to 48 families by morphological inspection of a single representative specimen. We then assigned ecological guilds at the family level, enabling joint assessment of taxonomic and functional diversity. Pan traps collected twice as many specimens and reached higher sample coverage than transect counts, while total MOTU richness was similar. However, assemblages differed in composition, indicating that the two methods are complementary, and still shared 27% to 40% of ecological-guild representation across habitats. Our integrative discovery framework reveals outstanding Diptera diversity and provides a scalable framework combining multiple sampling techniques with high-throughput molecular workflows, applicable to other neglected insect taxa and ecosystems.

Insect wings commonly have 2 types of veins: primary and secondary. Primary veins have fixed positions across members of a given species, while the number, position, and connections of secondary veins vary from wing to wing even within individuals. Relative to primary veins, very little is known about the patterning and development of secondary venation, in part because they cannot be analyzed with traditional morphometric approaches, which require the identification of homologous landmarks across wings. We present a landmark-free morphometric approach for analyzing secondary wing venation, and we use it to describe the effects of temperature on secondary vein patterns in the common cricket Acheta domesticus (Linnaeus 1758). Our principal components-based approach identified 3 major compartments to the wing within which we observed correlations among the shapes of domains formed by secondary veins. Most interestingly, the effects of temperature varied across these compartments: higher temperatures were associated with larger domains in one compartment, smaller domains in another, and had no marginal correlation with domain shape in a third. This suggests that secondary vein development may involve multiple independent patterning systems in different regions, or more likely, a system whose parameters vary across the wing field.

Oak galls are structures of modified plant tissue, induced by an ovipositing female oak gall wasp (Hymenoptera: Cynipidae: Cynipini), that provide food and shelter for her progeny. Myriad other wasp species exploit galls, feeding on either the gall wasp larva (parasitoidism), the gall tissue (inquilinism/kleptoparasitism), or other parasites within the gall (hyperparasitism). Though many oak gall-associated wasps are now described, their feeding ecology often remains poorly documented, particularly in the species-rich communities across North America. Wasps in the genus Euceroptres (Hymenoptera: Figitidae) exemplify this problem, long having been assumed to be inquilines based on limited evidence. We used dissections, microcomputed tomography scanning, and DNA barcoding to discover that Euceroptres do not modify the internal composition of their host gall. We also found a Euceroptres larva feeding on gall-inducer larva within an unaltered gall wasp larval chamber. Thus, Euceroptres are parasitoids, not inquilines. While sequencing larval and adult Euceroptres, we also found that the 2 previously described species in eastern North America, Euceroptres whartoni Buffington and Liljeblad, 2008 and Euceroptres primus Ashmead, 1896, did not separate into distinct clades, suggesting they are a single species. Subsequent morphological comparisons support this finding, allowing the establishment of E. whartoni as a syn. nov. of E. primus.

Despite the overwhelming diversity and ecological impact of insects across most ecosystems, their responses to environmental stress remain underexplored. To survive temperate seasonal stressors, particularly winter cold conditions and nutrient and water shortage, insects undergo physiological changes and overwinter in a diapause state. During diapause, cessation of development is coupled with reduced metabolic activity, analogous to hibernation in mammals, in which gut microbiota help manage waste and recycle nitrogen. Similarly, many insects have obligate symbiotic relationships with microbes that support nutrient acquisition. However, unlike mammals, many insects have open or transient gut communities, making it more likely that microbial dynamics are strongly shaped by environmental microbes acquired through food or habitat. This review synthesizes recent literature on the roles of host-associated microbial communities in insect diapause, spanning nutrient provisioning, nitrogen recycling, and host immunity, including how associated microbes contribute to pathogen defense during dormancy. We propose future research avenues for more mechanistic understanding of host-microbe interactions involved in diapause, drawing on conceptual parallels established from mammalian hibernation research.

[This corrects the article DOI: 10.1093/aesa/saag009.].

Leafhoppers (Hemiptera: Cicadellidae) use substrate-borne vibrations to communicate, and characteristics of these vibrational signals help identify, locate, and assess suitability of potential mates. The strength and frequency composition of signals influence behavioral responses in conspecifics. Leafhoppers are known to produce these vibrational signals while probing, but it is unclear whether this dual activity degrades signal transmission, inducing a trade-off between nutrient acquisition and mate attraction. In contrast, we hypothesized that inserted mouthparts could provide an additional point of contact with the plant, improving signal transmission. Here, we combine simultaneous electropenetrography (EPG) and accelerometer recordings to assess how beet leafhopper [Neoaliturus tenellus (Baker)] vibrational signals vary with probing behavior, including xylem ingestion, phloem salivation/ingestion, and probing of epidermis and mesophyll cells. Signals documented during 6-h recordings of male leafhoppers had significantly higher amplitude and dominant frequency when leafhoppers were probing than when they were not probing. However, the dominant frequency of signals was similar when leafhoppers were engaged in pathway phase, phloem ingestion, and xylem ingestion. Of the different probing behaviors, xylem ingestion had the strongest positive effect on signal amplitude, but phloem ingestion did not influence signal amplitude. Additional contact between the leafhopper and the plant surface, provided by leafhopper mouthparts, may improve vibration transmission, potentially increasing signal active space. In light of our finding that the act of probing plant tissues influences information conveyed in leafhopper vibrational signals, we suggest further research to evaluate the impacts these signal changes have on the behavior of other mates and natural enemies.

Extracellular vesicles (EVs) are nanoscale, lipid-bound structures released by cells across all domains of life. Once viewed as a means for discarding unwanted cellular components, they are now understood to be central mediators of intercellular communication. Much of what is known about EVs comes from mammalian systems, where extensive work has defined the major EV subtypes and the mechanisms that generate exosomes. These findings continue to serve as the primary reference for interpreting EV biology in other organisms. EVs have been isolated from diverse arthropods, including a few insect and tick species, yet the molecular pathways that produce them remain less characterized. Current evidence from Drosophila, mosquito cell lines, and tick systems shows that many of the core components driving exosome biogenesis in mammals, including ESCRT complexes, tetraspanins, lipid-modifying enzymes, Rab GTPases, and SNARE proteins, are present and, in several cases, experimentally validated in arthropods. These findings point to broad conservation of exosome biogenesis across taxa, while also highlighting key caveats, with most conclusions relying on only a small number of model systems. The definitions of EV subtypes remain unclear in many arthropods, and alternative EV biogenesis pathways have received little attention. Future studies that incorporate non-model species, apply rigorous EV characterization standards, and explore the roles of various EV subtypes will clarify how these pathways operate across arthropod lineages and how they differ from well-studied mammalian systems.

Understanding virus-vector-host interactions in the context of mixed infections is crucial to predict virus spread and develop effective control measures in economically important crops. The virus transmission process plays a central role in plant disease epidemiology and is particularly influenced by vector behavior and life-history traits. However, how mixed virus infections shape vector fitness and host preference remains poorly understood. Here, we determined the effects of double infections with the noncirculative cucumber mosaic virus (CMV, Cucumovirus) and the circulative cucurbit aphid-borne yellows virus (CABYV, Polerovirus) on the fitness and host plant preference of the aphid Aphis gossypii Glover on the host plant, melon (Cucumis melo L.). We revealed that aphids feeding on melon infected only with CMV (single-infected) weighed less and had lower fecundity than those feeding on uninfected plants or CABYV single- or double-infected plants. The mean relative growth rate and, consequently, the intrinsic rate of natural increase were also lower in aphids on CMV single-infected plants, indicating a negative impact of CMV single-infection on aphid fitness. In choice experiments, aphids were initially attracted to CABYV/CMV double-infected plants, but this was followed by a shift in host preference toward mock-inoculated plants over time. These findings suggest that mixed infections can modulate vector behavior in complex and dynamic ways. The pattern of early attraction followed by dispersal appears to promote CMV spread while having limited consequences for CABYV transmission, indicating an asymmetrical benefit between these 2 viruses.

The success of biological control of insect pests by parasitoids ultimately depends on effective host foraging by the agents, which involves multiple processes and various cues associated with hosts' habitat, host-associated symbionts and other microbial organisms, and/or hosts themselves. In general, parasitoid interactions with concealed hosts such as wood-boring beetles differ significantly from those that attack exposed hosts (eg surface-feeding caterpillars, aphids) as they must rely on a more complex hierarchy of cues to first locate hosts' microhabitats and then hosts for their reproduction. These differences influence the parasitoid's host-finding strategies, specificity, and their efficacy in suppressing their host populations. Here, we review the major steps in host finding by parasitoids of wood-boring beetles and synthesize current knowledge on the chemical, vibrational, visual, and other cues that mediate each stage of the process. We highlight how these cues operate across different spatial scales, interact with parasitoid morphology and behavior, and shape the success of biological control programs targeting economically important wood-boring pests. Finally, we identify key knowledges gaps and point to some future research directions aimed at improving the selection, deployment, and monitoring of parasitoid biological control agents in forest ecosystems.

Biological control through arthropod predation is one of the most economically important ecosystem services in agriculture. Because of this, documenting predator communities' ecological and behavioral responses to the environment and the resultant changes to predator activity and predation are crucial to agricultural sustainability. Temporal variability in resources, environmental conditions, and arthropod behavior is increasingly recognized for its ecological importance. However, this recognition is largely focused on shifts in diurnal aspects of the ecosystem. Nocturnal predation can match or exceed diurnal predation across predatory taxa, so ignoring nocturnal predation risks overlooking species that contribute significantly to predation services. This review assembles current knowledge about nocturnal predation in annual row crops, outlines its importance, and advocates for further work in this understudied area. Comprehensive identification of predator communities is quite rare, with nocturnal communities even more woefully under-researched than their diurnal counterparts. This represents a major blind spot in entomology, especially for predation ecology, and even persists where predation is known to primarily occur nocturnally, allowing severe underestimation of pest control by nocturnal predators. The more ephemeral nature of predation and the difficulty of direct documentation preclude many passive collection methods, especially for evaluating diel activity of the predatory complex in situ. Further, changing climates may differentially affect diurnal and nocturnal predators, leading to significant impacts on predation outcomes. Both nocturnal and diurnal predators face spiking temperatures and their associated desiccation threat and phenological shifts though different activity patterns will likely alter the impact of the changing climate on these predatory complexes.