Selection of Lactic Acid Bacteria Species and Strains for Efficient Trapping of Drosophila suzukii

SIMPLE SUMMARY: The spotted wing drosophila (SWD) is an invasive fruit fly that causes serious economic damage to many fruit crops. Monitoring is the first step for any management program to determine the characteristics of a pest. For this purpose, there are no efficient baits registered to date. Certain bacteria release chemical compounds that attract SWD. We studied the bacterial impact on the enhanced attractiveness of a commercial bait (Droskidrink(®)) under field and laboratory conditions. At first, Oenococcus oeni belonging to lactic acid bacteria (LAB) was found to release chemical compounds that were highly attractive for SWD. The attractiveness of Droskidrink(®) bait was increased by O. oeni culture, resulting in a higher capture rate of SWD in traps. Therefore, our findings suggest the use of the bacterial culture inside the commercial SWD baits. The use of these kinds of baits can minimize the risk of pest outbreaks in fruit orchards in both domestic and wild environments. Our pest management approach is farmer-friendly in all aspects, as well as the food sector. ABSTRACT: (1) Monitoring of Drosophila suzukii is based on the use of effective traps and baits. The current baits are insufficient to provide efficient monitoring. The use of bacteria as bio-catalyzers to produce bioactive volatiles may improve flies’ attraction. Thus, we conducted this work to improve Droskidrink(®) bait’s attractiveness using lactic acid bacteria. (2) Different baits that were based on the use of Droskidrink(®) were assessed for flies’ attraction in a Droso-Trap(®) in a vineyard. Oenococcus oeni, Pediococcus spp., and Lactobacillus spp. were used. The performance of the most attractive species, O. oeni, inoculated into Droskidrink(®) was assessed in laboratory tests. The responses of female flies to volatiles produced by Droskidrink(®) with O. oeni strains were recorded by electroantennography. (3) Preliminary field assessment of baits recorded O. oeni as the most attractive species. Three strain groups showed adaptation to test conditions. Volatiles extracted by the headspace of baits inoculated with O. oeni, elicited electroantennographic responses from fly antennae. (4) Droskidrink(®) inoculated with O. oeni is a highly attractive bait for monitoring. These findings will be useful for improving the attractiveness of D. suzukii commercial baits based on the utilization of LAB volatiles in a strain-dependent manner.