D3446: Spotted-wing drosophila management with stingers, sugars and sterility

Spotted-wing drosophila (SWD), Drosophila suzukii, is an invasive pest of small fruits and cherries. Alternative control measures to reduce insecticide use are being explored for SWD control. First, we have been making releases of the imported parasitoid Ganaspis brasiliensis in blueberry fields since 2022 and have recovered the parasitoid. Second, we are exploring the use of erythritol formulations, a food-grade insecticide. While erythritol can kill SWD, it also causes spotting on leaves. We are in the second year of studying potential phytotoxic effects on plants. First year data reveal no detectable impact on stomatal conductance, photosynthetic potential, water content, or solute concentration on treated cherry and blueberry plants. Third, we are working with a commercial company to test sterile males produced by CRSPR-CAS9 technology. A 5:1 release of sterile:wild males to 3 ft. cages with wild virgin females suppressed fruit infestation in the laboratory.