Plastic mulches alter the raspberry agroecosystem to improve management of spotted-wing drosophila

The invasive spotted-wing drosophila, Drosophila suzukii, is a major pest of fruit crops world-wide. Management of D. suzukii relies heavily on chemical control in organic and conventional systems, and there is a need to develop more sustainable management practices. We evaluated the viability of plastic mulches as a cultural control for D. suzukii in fall-bearing raspberry in a two year study. Black, white, and metallic plastic mulches reduced D. suzukii adult populations in the canopy and larval infestation of fruit compared to the control plots. Canopy temperature and humidity were not different between treatments. Metallic mulches increased light intensity in the canopy and all mulch treatments increased radiance of wavelengths visible to Drosophila, suggesting that light may be an important factor in deterring flies in the mulch treatments.  Our results suggest plastic mulches are a promising cultural control for D. suzukii since they can reduce adult and larval populations.