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

Amani Alawamleh, Gordana Ðurovi´c, Giuseppe Maddalena, Raffaele Guzzon, Sonia Ganassi, Maaz Maqsood Hashmi, Felix Wäckers, Gianfranco Anfora and Antonio De Cristofaro

INFORMATIVE ABSTRACT - Drosophila suzukii is a fruit fly originally from Southeast Asia that is becoming a major pest species in Europe and America. The peculiarity of this insect lies in the ability of the females to lay eggs even in healthy fruits as they are able to pierce the surface. The fruits consequently undergo a rapid decay. It represents a serious agriculture threat to fruit sector, because farmers doesn’t know how to challenge this new invasive species besides the use of insecticides. However, more sustainable methods are needed.

The study aims to demonstrate that there are new ways to face the arrival of Drosophila suzukii, and traps are the best way to monitor and study this insect . Researchers used a trap system using odours that attract flies, detecting the first spring arrival of the D. suzukii. The composition of the odorant substance is: mixture of wine, apple cider vinegar, and different commercially available strains of lactic acid bacteria. This substance is commercialized as a bait called Droskidrink.

Researchers studied the bacterial impact on the enhanced attractiveness of Droskidrink under field and laboratory conditions, and especially the lactic acid bacteria (LAB). Oenococcus oeni, Pediococcus, and Lactobacillus were used. Among these bacteria species, Oenococcus oeni strains was found as the most attractive species by electroantennography to release chemical compounds that were highly attractive for the D. suzukii when combined with Droskidrink. This compound of Droskidrink inoculated with O. oeni turns out to be therefore a highly attractive bait for monitoring.
The approach used in the research is farmer-friendly in all aspects, as well as the food sector.