insect chemosensory

Fig wasps (Agaonidae; Hymenoptera) are the only pollinating insects of fig trees (Ficus; Moraceae), forming the most closely and highly specific mutualism with the host. We used transcriptome sequences of 25 fig wasps from six genera to explore the evolution of key molecular components of fig wasp chemosensory genes: odorant-binding proteins (OBPs) and chemosensory proteins (CSPs). We identified a total 321 OBPs and 240 CSPs, with each species recording from 6 to 27 OBP genes and 6-19 CSP genes. 318 OBP genes are clustered into 17 orthologous groups and can be divided into two groups: PBP sensitive to pheromone and GOBP sensitive to general odor molecules, such as alcohols, esters, acids, ketones, and terpenoids...

Evidence for parental environments profoundly influencing the physiology, biology and neurobiology of future generations has been accumulating in the literature. Recent efforts to understand this phenomenon and its underlying mechanisms have sought to use species like rodents and insects to model multi-generational legacies of parental experiences like stress and nutritional exposures. From these studies, we have come to appreciate that parental exposure to salient environmental experiences impact the cadence of brain development, hormonal responses to stress, and the expression of genes that govern cellular responses to stress, in offspring...

The physiological state of an insect can affect its olfactory system. However, the molecular mechanism underlying the effect of nutrition-dependent states on odour-guided behaviours in hoverflies remains unclear. In this study, comparative transcriptome analysis of the antenna and proboscis from Eupeodes corollae under different feeding states was conducted. Compared with the previously published antennal transcriptome, a total of 32 novel chemosensory genes were identified, including 4 ionotropic receptors, 17 gustatory receptors, 9 odorant binding proteins and 2 chemosensory proteins...

Chemoreception is critical for the survival and reproduction of animals. Except for a reduced group of insects and chelicerates, the molecular identity of chemosensory proteins is poorly understood in invertebrates. Gastropoda is the extant mollusk class with the greatest species richness, including marine, freshwater, and terrestrial lineages, and likely, highly diverse chemoreception systems. Here, we performed a comprehensive comparative genome analysis taking advantage of the chromosome-level information of two Gastropoda species, one of which belongs to a lineage that underwent a whole genome duplication event...

Endoclita signifer is a prominent wood-boring insect species in eucalyptus plantations in Guangxi, China, causing significant ecological and economic damage. A novel approach to controlling the challenging wood-boring pest involves disrupting the olfactory communication between insects and the volatile compounds emitted by plants. To identify the olfactory proteins contributing to host selection based on 11 GC-EAD-active volatiles from eucalyptus leaves and to discover the highly expressed olfactory proteins, we conducted a study on the antennal transcriptomes of adult E...

In insects, the chemical senses influence most vital behaviors, including mate seeking and egg laying; these sensory modalities are predominantly governed by odorant receptors (ORs), ionotropic receptors (IRs), and gustatory receptors (GRs). The codling moth, Cydia pomonella , is a global pest of apple, pear, and walnut, and semiochemically based management strategies limit the economic impacts of this species. The previous report of expression of a candidate pheromone-responsive OR in female codling moth ovipositor and pheromone glands raises further questions about the chemosensory capacity of these organs...

Chemosensory proteins (CSPs) are a class of soluble proteins that facilitate the recognition of chemical signals in insects. While CSP genes have been identified in many insect species, studies investigating their function remain limited. Cotesia ruficrus (Hymenoptera: Braconidae) holds promise as an indigenous biological control agent for managing the invasive pest Spodoptera frugiperda (Lepidoptera: Noctuidae) in China. This study aimed to shed light on the gene expression, ligand binding, and molecular docking of CrufCSP1 in C...

In this paper, we take a historical perspective by going back to Verschaffelt's landmark study published in 1910, in which he found that glucosinolates were used as token stimuli by larvae of Pieris butterflies, specialist feeders on plants in the family Brassicaceae. This classic discovery provided key evidence for Fraenkel (Science 129:1466-1470, 1959) to elaborate on the function of secondary plant substances and for Ehrlich and Raven (Evolution 18:586-608, 1964) to put forward the hypothesis of insect-plant coevolution...

The chemosensory system is crucial during the growth and development of the moths. Spodoptera frugiperda (Lepidoptera: Noctuidae) is one of the most destructive insect pests. However, there is little functional research on odorant-binding proteins (OBPs) in the larval stage of S. frugiperda . Here, we obtained SfruOBP7 from transcriptomics and conducted the sequence analysis. We used quantitative real-time PCR to explore the expression profiles of SfruOBP7. The function identification showed that SfruOBP7 has a binding ability to 18 plant volatiles...

Chemoreception through odorant receptors (ORs), ionotropic receptors (IRs) and gustatory receptors (GRs) represents the functions of key proteins in the chemical ecology of insects. Recent studies have identified chemoreceptors in coleopterans, facilitating the evolutionary analysis of not only ORs but also IRs and GRs. Thus, Cerambycidae, Tenebrionidae and Curculionidae have received increased attention. However, knowledge of the chemoreceptors from Scarabaeidae is still limited, particularly for those that are sympatric...

Egg-laying behavior in insects has a dramatic impact on their fitness, controlling their extent and distribution across ecosystems. Thus, understanding the cues that guide mosquito egg laying is an important goal. Measuring mosquito egg-laying preference is critically important for understanding the sensory and neural mechanisms guiding adaptive breeding decisions. Here, we present a method for ascertaining the egg-laying preference of individual Aedes aegypti mosquitoes in small chambers with two distinct oviposition substrate choices...

Behavior evolution can promote the emergence of agricultural pests by changing their ecological niche. For example, the insect pest Drosophila suzukii has shifted its oviposition (egg-laying) niche from fermented fruits to ripe, nonfermented fruits, causing significant damage to a wide range of fruit crops worldwide. We investigate the chemosensory changes underlying this evolutionary shift and ask whether fruit sugars, which are depleted during fermentation, are important gustatory cues that direct D. suzukii oviposition to sweet, ripe fruits...

The surface of the insect body is covered with a hydrophobic layer called cuticular wax (CW). In addition to functioning as an anti-desiccation agent, CW is critical for chemical communication. It has been reported that in Chrysomelidae, males discriminate between sexes based on the sex-specific CW. However, little is known regarding the underlying sensory basis. Herein, we demonstrate that chemosensory input from mouthparts mediates sexual discrimination in male Galerucella grisescens (Chrysomelidae). Observations of mating behaviour, bioassays for CW, and chemical analyses revealed that G...

In the fruit fly Drosophila melanogaster , gustatory sensory neurons express taste receptors that are tuned to distinct groups of chemicals, thereby activating neural ensembles that elicit either feeding or avoidance behavior. Members of a family of ligand -gated receptor channels, the Gustatory receptors (Grs), play a central role in these behaviors. In general, closely related, evolutionarily conserved Gr proteins are co-expressed in the same type of taste neurons, tuned to chemically related compounds, and therefore triggering the same behavioral response...

Mosquitoes are effective vectors of deadly diseases and can navigate their chemical environment using chemosensory receptors expressed in their olfactory appendages. Understanding how chemosensory receptors are spatially organized in the peripheral olfactory appendages can offer insights into how odor is encoded in the mosquito olfactory system and inform new ways to combat the spread of mosquito-borne diseases. The emergence of third-generation hybridization chain reaction RNA whole-mount fluorescence in situ hybridization (HCR RNA WM-FISH) allows for spatial mapping and simultaneous expression profiling of multiple chemosensory genes...

The infective juveniles (IJs) of entomopathogenic nematode (EPN) Heterorhabditis bacteriophora find and infect their host insects in heterogeneous soil ecosystems by sensing a universal host cue (CO2 ) or insect/plant-derived odorants, which bind to various sensory receptors, including G protein-coupled receptors (GPCRs). Nematode chemosensory GPCRs (NemChRs) bind to a diverse set of ligands, including odor molecules. However, there is a lack of information on the NemChRs in EPNs. Here we identified 21 GPCRs in the H...

Grylloprimevala jilina is a true cave insect living in the dark areas of caves. It has the characteristics of sparse skin pigmentation, degeneration of the compound eyes and monocular eyes, and obvious preference for high-humidity and low-temperature environments. Given the highly specialized, rare, and limited distribution, G. jilina is considered an endangered species and also a first-level national protected insect in China. Cave creatures often undergo dramatic morphological changes in their sensory systems to adapt to the cave environment...

Termites are eusocial insects. Chemical signals between colony members are crucial to the smooth running of colony operations, but little is known about their olfactory system and the roles played by various chemosensory genes in this process. Chemosensory genes are involved in basic olfactory perception in insects. Odontotermes formosanus (Shiraki) is one of the most damaging pests to agricultural crops, forests, and human-made structures. To better understand the olfactory system and the genes involved in olfactory processing in O...

Lambda-cyhalothrin is one of the most important pyrethroids used for controlling wheat aphids. Extensive spraying of lambda-cyhalothrin has led to the development of high resistance to this pyrethroid in Rhopalosiphum padi . The mechanisms of resistance are complex and not fully understood. In this study, we found that a laboratory-selected strain of R. padi showed extremely high resistance to lambda-cyhalothrin and cross-resistance to bifenthrin and deltamethrin. The expression level of RpCSP7 was significantly elevated in the resistant strain compared to that in the susceptible strain...

The sophisticated olfactory system of insects is plays a critical role in detecting chemical signals and guiding insect behaviors, such as selecting mates, finding hosts, evading predators, and discovering oviposition sites. Therefore, exploring and clarifying the molecular processes of this system is crucial for developing new insecticides or efficient pest control methods. Plodia interpunctella (Hübner) is a disruptive insect pest damaging the stored grains over the world. However, the olfactory processes of P...