Search

Simple Summary: Microbial symbionts could intervene with the physiological processes of insect chemoreception, such as changing the processing, transmission, and integration of olfactory or gustatory signals and thereby improve or reduce insect sensitivity to semiochemicals, which in turn adjusts insect behavior. The influence of microbial symbionts on insect chemical communication facilitates the spread of symbionts but could be beneficial or detrimental to insects, which provides the impetus for the co-evolution of symbiotic systems. The association between microbial symbionts and insect chemoreception could be exploited to develop new insect control strategies. Chemical communication is widespread among insects and exploited to adjust their behavior, such as food and habitat seeking and preferences, recruitment, defense, and mate attraction. Recently, many studies have revealed that microbial symbionts could regulate host chemical communication by affecting the synthesis and perception of insect semiochemicals. In this paper, we review recent studies of the influence of microbial symbionts on insect chemoreception. Microbial symbionts may influence insect sensitivity to semiochemicals by regulating the synthesis of odorant-binding proteins or chemosensory proteins and olfactory or gustatory receptors and regulating host neurotransmission, thereby adjusting insect behavior. The manipulation of insect chemosensory behavior by microbial symbionts is conducive to their proliferation and dispersal and provides the impetus for insects to change their feeding habits and aggregation and dispersal behavior, which contributes to population differentiation in insects. Future research is necessary to reveal the material and information exchange between both partners to improve our comprehension of the evolution of chemoreception in insects. Manipulating insect chemoreception physiology by inoculating them with microbes could be utilized as a potential approach to managing insect populations. [ABSTRACT FROM AUTHOR]

Simple Summary: The red palm weevil (Rhynchophorus ferrugineus) is an invasive pest that causes severe economic loss in palm plant cultivation (e.g., oil palm, date, and coconut) in many regions of the world. The development of efficient approaches to controlling this pest is urgently needed. Previous research focused on the molecular basis of its olfaction, leading to the identification of this species' aggregation pheromone receptor, which can help develop biosensors and bait traps. To gain more understanding of the chemoreception in this species, we used a bioinformatic approach to identify all the gustatory receptor genes from its genome and transcriptome data. There are 50 gustatory receptor genes encoding 65 functional receptors, including CO2, sugar, and bitter receptors. Our results will help elucidate how this beetle discriminates and evaluates food and egg-laying sites and communicates via gustation. The red palm weevil (Rhynchophorus ferrugineus) is a highly destructive pest of oil palm, date, and coconut in many parts of Asia, Europe, and Africa. The Food and Agriculture Organization of the United Nations has called for international collaboration to develop a multidisciplinary strategy to control this invasive pest. Previous research focused on the molecular basis of chemoreception in this species, particularly olfaction, to develop biosensors for early detection and more effective bait traps for mass trapping. However, the molecular basis of gustation, which plays an essential role in discriminating food and egg-laying sites and chemical communication in this species, is limited because its complete gustatory receptor gene family still has not been characterized. We manually annotated the gene family from the recently available genome and transcriptome data and reported 50 gustatory receptor genes encoding 65 gustatory receptors, including 7 carbon dioxide, 9 sugar, and 49 bitter receptors. This study provides a platform for future functional analysis and comparative chemosensory study. A better understanding of gustation will improve our understanding of this species' complex chemoreception, which is an important step toward developing more effective control methods. [ABSTRACT FROM AUTHOR]