Identification And Expression Of Olfactory Genes And Trapping Protocols Of Pheromone In Rhynchophorus Ferrugineus(olivier)

The red palm weevil(RPW),Rhynchophorus ferrugineus(Coleoptera: Rhynchophoridae),is one of the most important invasive pests to palms,which seriously affects the construction of tropical ecology and the development of regional economy in China.Insect olfaction plays an important role in host location,reproduction and avoidance of natural enemies,and chemoreceptor protein is the molecular basis of insect olfaction.However,In this study,we focused on the artificial feeding technology,affecting factors on identification and function analysis of chemoreceptor genes and capture efficacy of aggregation pheromone traps.Main conclusions are as follow:Developed a semi-artificial diet for RPW with the old leaves of royal palm as the main component.The growth duration of the generation fed on the semi artificial diet was significantly shorter than that of the natural host,the survival rate of the larvae was significantly higher than that of the natural host.Besides,the semi-artificial can continuously feed many generations of RPW.Based on the genome of the RPW,41 OBPs genes,11 CSPs genes,64 ORs genes,19 GR genes,27 IR genes and 7 SNMP genes were identified.The number of OR,GR and IR identified are all less than the number of genes identified in the genomes of Tribolium castaneum and Leptinotarsa decemlineata,indicating that there is a significant contraction compared with these two species.Analyze the expression level of each gene in different developmental stages and different tissues based on the expression profile,and use clustering to analyze the expression characteristics of these genes.Through analysis,it was found that whether it is in different tissues or between different genders,the highly expressed OBPs,CSPs,ORs,GRs,IRs and SNMPs genes are more antenna than other tissues,indicating that the gene expression level has organizational differences.RNAi technology was used to silence 10 OBP,18 or and 7 SNMP genes.q PCR analysis showed that the RNAi silencing effect of the genes injected with ds RNA was better than that of the control,the expression of which was less than 60% of that of the control,and the best one was 10% left and right.The results of EAG and Y-olfactometer showed that the behavioral responses of the above genes to the main components of aggregation pheromone decreased significantly after silencing,indicating that these genes play an important role in the recognition of aggregation pheromone.The effects of trap types,colors,heights and spacing on pheromone trapping were compared,shows that the best trapping effect is when the red cross trap is placed on the ground and the distance between traps is 100 m.The life span and reproductive ability of the female adults trapped by pheromone were studied.It was found that the majority of the female adults were gravid,and the age of the females was relatively small,which indicated that pheromone could be widely used in the control of RPW.