Current opinion in insect science最新文献

Diapause is an endocrine-mediated strategy used by insects to survive seasons of adverse environmental conditions. Insects living in temperate zones are regularly exposed to such conditions in the form of winter. To survive winter, they must prepare for it long before it arrives. A reliable indicator of impending winter is the shortening of day length. To measure day length, insects need their circadian clock as internal time reference. In this article, I provide an overview of the current state of knowledge on the neuropeptides that link the clock to the diapause inducing hormonal brain centers.

Ant colonies are organized in castes with distinct behaviors that together allow the colony to strive. Reproduction relies on one or a few queens that stay in the nest producing eggs, while females of the worker caste do not reproduce and instead engage in colony maintenance and brood caretaking. Yet, in spite of this clear separation of functions, workers can become reproductive under defined circumstances. Here, we review the context in which workers become reproductive, exhibiting asexual or sexual reproduction depending on the species. Remarkably, the activation of reproduction in these workers can be quite stable, with changes that include behavior and a dramatic extension of lifespan. We compare these changes between species that do or do not have a queen caste. We discuss how the mechanisms underlying reproductive plasticity include changes in hormonal functions and in epigenetic configurations. Further studies are warranted to elucidate not only how reproductive functions have been gradually restricted to the queen caste during evolution but also how reproductive plasticity remains possible in workers of some species.

Insects rely heavily on their olfactory system for various behaviors, including foraging, mating, and oviposition. Numerous studies have demonstrated that insects can adjust their olfactory behaviors in response to different physiological states and environmental conditions. This flexibility allows them to perceive and process odorants according to different conditions. The Oriental fruit fly, Bactrocera dorsalis, is a highly destructive and invasive pest causing significant economic losses to fruit and vegetable crops worldwide. The olfactory behavior of B. dorsalis exhibits strong plasticity, resulting in its successful invasion. To enhance our understanding of B. dorsalis’ olfactory behavior and explore potential strategies for behavior control, we have reviewed recent literature on its olfactory plasticity and potential molecular mechanisms.

Mosquitoes encounter diverse microbes during their lifetime, including symbiotic bacteria, shaping their midgut ecosystem. The organization of the midgut supports microbiota persistence while defending against potential pathogens. The influx of nutrients during blood feeding triggers bacterial proliferation, challenging host homeostasis. Immune responses, aimed at controlling bacterial overgrowth, impact blood-borne pathogens such as malaria parasites. However, parasites deploy evasion strategies against mosquito immunity. Leveraging these mechanisms could help engineer malaria-resistant mosquitoes, offering a transformative tool for malaria elimination.

Mosquitoes are vectors for arboviruses, such as dengue, Zika, and Chikungunya. Symbiotic interactions can affect the intrinsic ability of mosquitoes to acquire and transmit arboviruses, referred to as vector competence. Insect-specific viruses (ISVs) are commonly found in symbiotic associations with mosquitoes in the wild and can affect many aspects of mosquito biology. Here, we review current knowledge on the effects of symbiotic ISV–mosquito interactions on vector competence. We discuss potential mechanisms underlying these interactions and their implications for shaping new biological control strategies. Finally, we highlight the need for field data analyzing the circulation of ISVs in mosquitoes associated with mechanistic studies in the laboratory.

Insect gut bacteria have been implicated in a myriad of physiological processes from nutrient supplementation to pathogen protection. In fact, symbiont-mediated insecticide degradation has helped explain sudden control failure in the field to a range of active ingredients. The mechanisms behind the loss of susceptibility are varied based on host, symbiont, and insecticide identity. However, while some symbionts directly break down pesticides, others modulate endogenous host detoxification pathways or involve reciprocal degradation of insecticidal and bactericidal compounds both inspiring new questions and requiring the reexamination of past conclusions. Good steward of the chemical pesticide arsenal requires consideration of these ecological interactions from development to deployment.

Low temperatures are rarely experienced in isolation. The impacts of low temperatures on insects can be exacerbated or alleviated by the addition of other environmental factors, including, for example, desiccation, hypoxia, or infection. One way in which environmental factors can interact is through cross-talk where different factors enact common signaling pathways. In this review, I highlight the breadth of abiotic and biotic factors that can interact with low-temperature tolerance in both natural and artificial environments; and discuss some of the candidate pathways that are possibly responsible for cross-talk between several factors. Specifically, I discuss three interesting candidates: the neurohormone octopamine, circadian clock gene vrille, and microbes. Finally, I discuss applications of cross-talk studies, and provide recommendations for researchers.

The continuous use of insecticides over the last eight decades has led to the development of resistance to these insecticides. Research in the last few decades showed that the mechanisms underlying resistance are diverse but can generally be classified under several modes of resistance such as target-site resistance, metabolic resistance, and penetration resistance. In this review, we highlight new discoveries in insecticide resistance research made over the past few years, including an emerging new mode of resistance, sequestration resistance, where the overexpression of olfactory proteins binds and sequesters insecticides in resistant strains, as well as recent research on how posttranscriptional regulation can impact resistance. Future research will determine the generality of these emerging mechanisms across insect species.

Detecting looming motion directly towards the insect is vital to its survival. Looming detection in two insects, flies and locusts, is described and contrasted. Pathways using looming detectors to trigger action and their topographical layout in the brain is explored in relation to facilitating behavioural selection. Similar visual stimuli, such as looming motion, are processed by nearby glomeruli in the brain. Insect-inspired looming motion detectors are combined to detect and avoid collision in different scenarios by robots, vehicles and unmanned aerial vehicle (UAV)s.

In social insects, interactions among colony members trigger caste differentiation with morphological modifications. During caste differentiation in termites, body parts and caste-specific morphologies are modified during postembryonic development under endocrine controls such as juvenile hormone (JH) and ecdysone. In addition to endocrine factors, developmental toolkit genes such as Hox- and appendage-patterning genes also contribute to the caste-specific body part modifications. These toolkits are thought to provide spatial information for specific morphogenesis. During social evolution, the complex crosstalks between physiological and developmental mechanisms should be established, leading to the sophisticated caste systems. This article reviews recent studies on these mechanisms underlying the termite caste differentiation and addresses implications for the evolution of caste systems in termites.