Molecular Diversity Of Bacterial Community In The Reproductive System And The Study Of Attraction Of Bactrocera Dorsalis (Diptera: Tetriphitidae)

The oriental fruit fly, Bactrocera dorsalis (Hendel), is one of the most destructive pests in China. This species can cause severe economic loss to more than 150 fruit crops. It is widely accepted that most insect species are inhabited by large and diverse microbial communities resident in their digestive system and bacterial contribution to the metabolism of insect host has also been documented. However, a little attention was paid to the bacteria located in the reproductive tract of insect. Here, we reported the bacterial species inhabited in the reproductive tract of male and female oriental fruit flies by using 16S rRNA-based PCR-DGGE. Further more, we tested if metabolites of bacterial species were attractive to this fruit fly species to get better lures to control this pest.From the reproductive tracts of females, we obtained 30 bacterial genotypes which belonged to five bacterial classes such as Betaproteobacteria, Alphaproteobacteria, Gammaproteobacteria, Bacilli and Actinobacteria. Twenty species of bacteria were obtained in Gammaproteobacteria which was the dominant ones in the whole bacterial community. The twenty species of bacteria were from six genuses such as Morganella, Kluyvera, Citrobacter, Raoultella, Enterobacter and an unknown genus of Enterobacteriae. Simultaneously, we also identified five species of bacteria in Bacilli, three species in Betaproteobacteria, one species in Alphaproteobacteria and one species in Actinobacteria.Compared with the bacteria from females, we only found 19 bacterial genotypes from males which belonged to four bacterial classes such as Betaproteobacteria, Alphaproteobacteria, Gammaproteobacteria and Bacilli. We found 11 species of bacteria in the dominant class Gammaproteobacteria which occupied 57.89% in the bacterial community within the male's reproductive tract.Finally, we got ten species of bacteria from females by combined using 16S rRNA-based PCR-DGGE and API20E Kits (Germany) which were Raoultella planticola, Enterobacter aerogenes, Enterobacter gergoviae, Enterobacter amnigenus, Raoultella ornithinolytica, Enterobacter sakazakii, Enterobacter cloacae, Klebsiella pneumoniae subsp.pneumoniae, Raoultella terrigena and Klebsiella oxytoca. The bioassay results showed that the fermentation liquor from Raoultella terrigena, Klebsiella oxytoca and Raoultella planticola were attractive to B. dorsalis. That of Raoultella terrigena performed the strongest trapping ability, the second is Klebsiella oxytoca.