Abstract:

【Aim】 The aim of this study is to determine the attractiveness of intestinal bacterium Klebsiella oxytoca to Drosophila suzukii, and to identify and verify the attractiveness of its volatile substances to D. suzukii adults. 【Methods】 The proportions of D. suzukii adults attracted by supernatants of K. oxytoca and NB medium (the control) as well as the proportions of female and male adults attracted in the presence or absence of host plant (Kyoho grape), respectively, were measured and analyzed. Volatile substances in the supernatant of K. oxytoca and NB medium were identified using HS-SPME-GC-MS methods. The attractiveness of four volatile substances of K. oxytoca supernatant with higher concentrations to D. suzukii adults was tested. 【Results】 D. suzukii adults were attracted to the supernatant of K. oxytoca. In the absence of host plant, the supernatant of K. oxytoca showed stronger attractiveness to male adults of D. suzukii than to female adults. However, in the presence of host plants, the numbers of female and male adults attracted by K. oxytoca supernatant were not significantly different. Twenty-one volatile substances were detected from K. oxytoca supernatant, among which 3-methyl-1-butyl alcohol, 2-phenylethyl alcohol, isoamyl acetate and indole had higher concentrations. D. suzukii adults showed taxis to 3-methyl-1-butyl alcohol, 2-phenylethyl alcohol and indole, but showed repellence to isoamyl acetate. The volatile substance 3-methyl-1-butyl alcohol could attract more male adults than female adults. 【Conclusion 】 Intestinal microorganism K. oxytoca supernatant can be used to attract D. suzukii adults, and 3-methyl-1-butyl alcohol is an important metabolite of K. oxytoca for attracting male adults of D. suzukii. This study provides some basic data for the control of D. suzukii.

Key words: Drosophila suzukii, Klebsiella oxytoca, gut microbiota, volatile substance, 3-methyl-1-butyl alcohol, attractiveness