Molecular Detection Of Wolbachia And Impact On Fitness Of Echinothrips Americanus Morgan

The invasive species Echinothrips americanus Morgan,1913belongs toPanchaetothripinae of Thripidae in sub-order Terebrantia of Thysanoptera. E. americanuswas first reported in the Eastern part of the USA and recently found in mainland China.E.americanus have a broad host plant range, posing a potential threat to ornamentals andgreenhouse crops. Wolbachia is a matemally inherited intracellular bacteria that infect a widerange of arthropods. Wolbachia has rugulated the reproduetive biology of their hosts toincrease their density distribution, including cytoplasmic incompatibility (CI),parthenogenesis induction (PI), male-killing and feminization. The present paper using wspgene sequences to detect the site of infection of Wolbachia in E.americanus, and using themethod of population ecology and molecular biology to investigated the ecological fitness ofE.americanus. The result will rich the infections of Wolbachia in nature and offer the theorysupports for the application of these endosymbionts in pest control. The result shows:1. The E. americanus was infected by endosymbiont Wolbachia. A phylogenetic analysisof Wolbachia based on632bp region of Wolbachia wsp gene (GenBank accesstion number isJN315668),580bp region of A group wsp gene and405bp region of Mel subgroup wsp genewere implementation in this paper. The topology of the phylogenetic tree showed that theWolbachia in E. americanus belonged to Mel subgroup of A group wsp gene.2. Wolbachia was found in the head,thorax and abdomen of infected E. americanus byPCR targeted sequences. This result suggested that Wolbachia has widely distribution in the E.americanus.3. The results showed that the preoviposition period, oviposition period and longevity ofWolbachia-infected female adults were longer than those Wolbachia-free. Furthermore,Wolbachia-free female adults had lower fecundity than Wolbachia-infected. However, nosignificant differences were found among immature stages in the durations of first and secondinstars, and pupae between Wolbachia-infected and Wolbachia-free.The removal of Wolbachia infection had the negative effects on the fitness ofE.americanus, expressed as control had the highest Intrinsic rate of increase values(0.0632),In contrast, for Wolbachia-free, its had the lower Intrinsic rate of increase values(0.0484).