Identification and evaluation of cultivable gut bacteria associated with peach fruit fly, Bactrocera zonata (Diptera: Tephritidae)

The aim of the present study was to identify the cultivable gut bacteria associated with peach fruit fly, Bactrocera zonata, and evaluate their potential to attract adults of B. zonata. Based on culture-dependent characterization methods and 16S rRNA gene sequence analysis, bacteria were identified as members of family Enterobacteriaceae (BZM1, Klebsiella oxytoca), Microbacteriacea (BZM2, Microbacterium spp.) and Nocardiaceae (BZM4, Rhodococcus spp.). Molecular phylogeny placed Klebsiella oxytoca within gram negative gamma-proteobacteria whereas, Microbacterium spp. and Rhodococcus spp. were clustered under gram positive Actinobacteria group in family Microbacteriacea and Nocardiaceae, respectively. 16S rRNA gene sequence comparison with the available NCBI database sequences further confirmed the characterizations of bacterial symbionts. Population of these bacterial species increased significantly up to the 11th day after emergence of adults and thereafter it remains constant. Among 3 bacterial symbionts, metabolites produced from K. oxytoca had the highest attraction to the B. zonata adult females over metabolites produced from other bacteria and their combinations in field bioassay. The B. zonata adult male flies attracted to metabolites produced from each bacterial symbionts alone and their combinations were less in number with comparison to the B. zonata adult females. The present study provides the first description of the attractancy potential of metabolites produced by gut microbial community of B. zonata in open field condition. This study results may prompt the development of a female-targeted population control strategy for this fly.