Repellency of aromatic plants essential oils towards Drosophila suzukii.

The Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is causing severe economic losses to various fruit crops, grapes included. Due to its relatively short life cycle, D. suzukii is able to complete several generations per year, so that frequent applications of insecticides are needed for its control and more eco-friendly control methods against this pest are expected. Essential oils (EOs) represent a very promising alternative to conventional insecticides because of their low environmental and mammalian toxicity. Here we evaluated the repellency of mandarin Citrus reticolata Blanco, and tea tree Melaleuca alternifolia (Maiden & Betche) Cheel EOs against adults of SWD. The chemical composition of the two EOs was assessed by GC-MS analysis. EOs were tested by two-choice still-air arena bioassays. Results showed a negative chemotaxis of SWD adults to both the essential oils at 1 and 10%. Tea tree EO exerted a stronger repellent activity in comparison with the mandarin EO.