摘要: Worldwide, pine forests have been threatened by a devastating pine wood disease caused by Bursaphelenchus xylophilus, with Monochamus saltuarius being a newly recorded vector of the disease in Northeast China. The olfactory system plays important roles in both feeding and oviposition during the adult stage of M. saltuarius, and olfactory gene function research is essential for gaining an understanding of the olfactory mechanisms of this pest. However, there is limited information available regarding olfactory gene functions in this pest. In the present study, we selected 7 olfactory genes, including 2 chemosensory proteins, 2 odorant-binding proteins, the odorant co-receptor and 2 odorant receptors, which were relatively highly expressed during the adult stage. We silenced these genes by RNA interference (RNAi), and real-time quantitative PCR was used to detect their expression levels after double-stranded RNA (dsRNA) injection. The results indicate that these genes were significantly downregulated at 2 d post-dsRNA injection, and this was sustained until 5 d post-injection. Electroantennography tests indicated that the knockdown of MsalOBP14 and MsalOrco impaired the olfactory response of M. saltuarius to 11 host volatiles and 1 sex pheromone compound. Y-tube experiments further confirmed that downregulated MsalOBP14 and MsalOrco expression led to olfactory dysfunction in M. saltuarius, which significantly lost selectivity. The results indicate that MsalOBP14 and MsalOrco play critical roles in sex communication and host volatile detection in M. saltuarius, and possibly represent 2 effective targets for controlling this forest pest through olfactory disruption.

摘要: Mantodea (praying mantises) is a group of exclusively predatory insects, which, together with nonraptorial blattodeans (cockroaches and termites) and groups exclusively found in the fossil record, form the group Dictyoptera. A central characteristic of Mantodea is the specialization of their first pair of legs as raptorial grasping appendages, but the evolution from walking to raptorial legs is not yet fully understood. Here, we trace the evolution of the raptorial appendages in Dictyoptera through time using a morphometric (morphospaces) approach. We also describe two new mantodean nymphs preserved in amber from the Cretaceous and Eocene, which expand the scarce mantodean fossil record. Blattodean and mantodean appendages appear distinct in morphospace, but several appendages of fossil non-mantodeans can be considered raptorial, providing a potential transitional link between walking and raptorial morphotypes. Therefore, we discuss potential mantodean affinities for other predatory fossil dictyopterans. We examine changes across extant mantodeans, characterized by a straightening of the tibia especially associated with the rise of the diversification of the Mantidea and discuss whether a thickening of the femur could reflect an early adaptation to cursorial hunting. This study traces changes in the morphology of the forelegs across fossil and extant dictyopterans to understand their evolution from cursorial limbs to the raptorial morphologies of mantodeans. Two new mantodean specimens preserved in amber are described herein. A principal component anlysis shows that changes in the shape of the tibia and the length of the femur were key to the evolution of the raptorial appendages, changes which could have been associated with differen predatory strategies. image

摘要: Ants are ubiquitous and eusocial insects that exhibit frequent physical contact among colony members, thereby increasing their susceptibility to diseases. Some species are often found in beehives and in their surroundings, where they exploit the food resources of honey bees. This intricate relationship may facilitate the interspecific transmission of honey bee pathogens to ants, although ants themselves may contribute to spillback phenomena. The objective of this study was to assess the presence and abundance of honey bee pathogens in ants sampled from Italian apiaries. A total of 37 colonies within 24 apiaries across 7 regions were monitored. In total, 6 pathogens were detected in adult ants and 3 in the brood. In particular, the study revealed a high prevalence of honey bee pathogens in ants, with DWV, BQCV, and CBPV being the most commonly encountered. The brood also tested positive for the same viruses. Notably, all analyzed viruses were found to be replicative in both adult ants and ant broods. Furthermore, co-infections were prevalent, suggesting complex pathogen interactions within ant populations. Statistical analysis indicated significant differences in pathogen prevalence and abundance among ant species and sample types. The findings highlight active infection in both the ants and the brood, suggesting a potential role of ants as reservoir hosts and vectors of honey bee pathogens emphasizing the need for further research to understand the implications of interspecific pathogen transmission on ant and bee health.

摘要: The insect cuticle, which serves as both a protective barrier and an efficient lever system for locomotion, is an extracellular matrix primarily composed of chitin and protein. The cuticle protein CPCFC characterized by a CFC motif containing 2 Cys split by the insertion of 5 residues is distributed across most insect species and specifically localized in the hard part of the cuticle. However, their physiological function is not fully understood. Here, we report 2 CPCFC proteins, TcCPCFC1 and TcCPCFC2, derived from the Coleopteran insect Tribolium castaneum. We revealed that TcCPCFC1 and TcCPCFC2 were predominantly expressed during the larval and adult stages of T. castaneum, respectively. The transcription downregulation of TcCPCFC1 significantly decreased the modulus and toughness of the elytral cuticle. We found that TcCPCFC proteins have high binding affinity to chitin. We cloned and produced recombinant TcCPCFC proteins and demonstrated that the addition of TcCPCFC proteins to chitin hydrogel greatly enhanced the hydrogel's modulus and toughness by forming denser chitin fibrous networks. Our findings reveal the functional role of CPCFC proteins in enhancing mechanical properties of insect cuticle, and we validate this process in vitro, and offer a protein candidate for fabrication of advanced chitin-based materials. The cuticular proteins of the CPCFC protein family interact with chitin fibers, modifying their structure within the chitin network. These interactions enhance the energy absorption capacity of the cuticle structure and improve its toughness. image

摘要: An essential adaptive strategy in insects is the evolution of olfactory receptors (ORs) to recognize important volatile environmental chemical cues. Our model species, Ceratosolen fusciceps, a specialist wasp pollinator of Ficus racemosa, likely possesses an OR repertoire that allows it to distinguish fig-specific volatiles in highly variable environments. Using a newly assembled genome-guided transcriptome, we annotated 63 ORs in the species and reconstructed the phylogeny of Ceratosolen ORs in conjunction with other hymenopteran species. Expression analysis showed that though ORs were mainly expressed in the female antennae, 20% were also expressed in nonantennal tissues such as the head, thorax, abdomen, legs, wings, and ovipositor. Specific upregulated expression was observed in OR30C in the head and OR60C in the wings. We identified OR expression from all major body parts of female C. fusciceps, suggesting novel roles of ORs throughout the body. Further examination of the OR expression of C. fusciceps in widely separated geographical locations, that is, South (urban) and Northeast (rural) India, revealed distinct OR expression levels in different locations. This discrepancy likely parallels the observed variation in fig volatiles between these regions and provides new insights into the evolution of insect ORs and their expression across geographical locations and tissues. center dot Our model species, Ceratosolen fusciceps, a specialist wasp pollinator of Ficus racemosa, likely possesses an olfactory receptor (OR) repertoire that enables it to distinguish fig-specific volatiles in highly variable environments.center dot Using a newly assembled genome-guided transcriptome, we annotated 63 ORs in the species and reconstructed the phylogeny of Ceratosolen ORs in conjunction with other hymenopteran species.center dot Expression analysis indicated that although ORs were mainly expressed in the female antennae, 20% were also expressed in nonantennal tissues.center dot OR expression of C. fusciceps in widely separated geographical locations, that is, South (urban) and Northeast (rural) India, revealed distinct OR expression in different locations.center dot This discrepancy likely parallels the observed variation in fig volatiles between these regions and provides new insights into the evolution of insect ORs and their expression across geographical locations and tissues. image

摘要: The ubiquitous incorporation of plastics into daily life, coupled with inefficient recycling practices, has resulted in the accumulation of millions of metric tons of plastic waste, that poses a serious threat to the Earth's sustainability. Plastic pollution, a global problem, disrupts the ecological balance and endangers various life forms. Efforts to combat plastic pollution are underway, with a promising avenue being biological degradation facilitated by certain insects and their symbiotic gut microorganisms, particularly bacteria. This review consolidates existing knowledge on plastic degradation by insects and their influence on gut microbiota. Additionally, it delves into the potential mechanisms employed by insects in symbiosis with gut bacteria, exploring the bioconversion of waste plastics into value-added biodegradable polymers through mineralization. These insights hold significant promise for the bio-upcycling of plastic waste, opening new horizons for future biomanufacturing of high-value chemicals from plastic-derived compounds. Finally, we weigh the pros and cons of future research endeavors related to the bioprospection of plastic-degrading bacteria from underexplored insect species. We also underscore the importance of bioengineering depolymerases with novel characteristics, aiming for their application in the remediation and valorization of waste plastics. Accumulation of plastic waste is a serious threat to global sustainability. Insect gut bacterial symbionts are potential agents for up-recycling of waste plastics. Possibilities for engineering the insect gut microbiome for plastic degradation are discussed. Key challenges toward microbial degradation of plastics are discussed. Future directions to understand host-microbial interplay are elucidated. image

摘要: Ciliary neurotrophic factor (CNTF) acts as a potent neuroprotective agent in neuronal survival and regeneration, and can also induce the differentiation of several stem cells into neurons, which highlights the broad application of CNTF in biomedicine. However, large-scale production of bioactive recombinant human CNTF protein remains to be explored. Herein, this study aims to express a bioactive human CNTF protein on a large scale by genetically engineering a silk gland bioreactor of silkworm. Our results showed that CNTF protein was successfully expressed in the middle silk gland (MSG) of silkworm, which can be secreted into the silks with the amount of 3.2 mg/g cocoons. The fabrication of human CNTF-functionalized silk material was able to promote proliferation and migration of neural cells when compared to the natural silk protein. Importantly, this functional silk material could also facilitate neurite outgrowth of mouse retinal ganglion cell (RGC-5) cells. All these data demonstrated a high bioactivity of the recombinant human CNTF protein expressed in the MSG of silkworm. The further fabrication of different silk materials with CNTF bioactivity will give biomedical applications in tissue engineering and neuroregeneration. We have established an efficient strategy for the large-scale and cost-effective production of bioactive human ciliary neurotrophic factor (CNTF) in silkworm. The fabrication of human CNTF silk material can promote proliferation, migration, and neurite outgrowth of neural cells. These data will provide biomedical applications in tissue engineering and neuroregeneration by using functionalized CNTF materials. image

摘要: Drosophila suzukii is a notorious pest which causes devastating damage to thin-skinned fruits, and the larvae feed on the fruit, causing extensive agricultural economic loss. The current application of insecticides to manage this pest results in serious resistance and environmental hazards, so an alternative strategy for D. suzukii biocontrol is urgently needed. Here, we reported that entomopathogenic Bacillus cereus has the potential to biocontrol D. suzukii. We isolated and identified the bacterial strain, B. cereus H1, that was detrimental to the fitness of both D. suzukii progenies and parents. D. suzukii was robustly repelled to depositing eggs on the halves with metabolites of B. cereus H1. Both males and females of D. suzukii were susceptible to B. cereus H1. B. cereus H1 significantly arrested larval development with at least 40% lethal larvae. The median lethal time (LT50) of males and females of D. suzukii challenged with B. cereus H1 was 3 and 2 d, respectively. Moreover, B. cereus H1 disrupted the intestinal integrity and pH value of D. suzukii and resulted in an increase in bacterial load of guts and hemolymph. Mechanistically, infection of B. cereus H1 led to the activation of the dual oxidase (DUOX)-ROS-Jun N-terminal kinase (JNK) pathway. The findings showed that the entomopathogen B. cereus H1 could potentially act as a biological control agent against D. suzukii, advancing fundamental concepts of integrated pest management programs against D. suzukii.

摘要: Knowing how environmental conditions affect performance traits in pest insects is important to improve pest management strategies. It can be informative for monitoring, but also for control programs where insects are mass-reared, and field-released. Here, we investigated how adult thermal acclimation in sterile Bactrocera dorsalis affects dispersal and recapture rates in the field using a mark-release-recapture method. We also considered how current abiotic factors may affect recapture rates and interact with thermal history. We found that acclimation at 20 or 30 degrees C for 4 d prior to release reduced the number of recaptures in comparison with the 25 degrees C control group, but with no differences between groups in the willingness to disperse upon release. However, the deleterious effects of acclimation were only detectable in the first week following release, whereafter only the recent abiotic conditions explained recapture rates. In addition, we found that recent field conditions contributed more than thermal history to explain patterns of recaptures. The two most important variables affecting the number of recaptures were the maximum temperature and the average relative humidity experienced in the 24 h preceding trapping. Our results add to the handful of studies that have considered the effect of thermal acclimation on insect field performance, but notably lend support to the deleterious acclimation hypothesis among the various hypotheses that have been proposed. Finally, this study shows that there are specific abiotic conditions (cold/hot and dry) in which recaptures will be reduced, which may therefore bias estimates of wild population size.

摘要: The rise of biological invasions threatens biodiversity and food security, with the vespid family, including Vespa soror, being of particular concern. Our study focused on the alarm pheromone components of V. soror. By using gas chromatography-mass spectrometry (GC-MS) chemical analyses, electroantennograms, and field bioassays, we identified 5 compounds-2-pentanol, 3-methyl-1-butanol, 2-heptanol, 2-nonanol (2-N), and isopentyl acetate (IPA)-in hornet sting venom that elicited defensive behavior from hornets. IPA and 2-N also serve as alarm pheromone components in multiple honey bee species that are important prey for V. soror. This shared chemical signaling may allow cross-detection by each species on the other's alarm cues. While it should be advantageous for bees to detect V. soror alarm pheromone, the benefits to V. soror of using IPA and 2-N are unclear. V. soror may manipulate bee behavior, potentially distracting defenders, because they mark victim bee colonies by rubbing their abdomens, which contain their sting glands, at bee hive entrances. Our findings pose new evolutionary questions about the role of manipulation in the arms races.