Adult reproductive diapause in Drosophila suzukii females

Drosophila suzukii (Diptera: Drosophilidae) is an emerging pest of soft fruits, but in this species diapause has not been thoroughly explored. We examined the effects of different temperatures and photoperiods on diapause induction and termination under laboratory conditions. There was variation in the ovarian development and oviposition rate under different photoperiods at 10 +/- 1 A degrees C, and the percentage of adults with immature ovaries was higher during the short photoperiod (8L:16D) than other photoperiods at 10 +/- 1 A degrees C. Adults were most sensitive to photoperiod within 3 days of eclosion. The optimal combination of photoperiod and temperature for diapause termination was a long photoperiod (16L:8D) at 25 +/- 1 A degrees C. The supercooling point was significantly reduced in reproductive diapause females, and trehalase, pyruvate kinase, sorbitol dehydrogenase, hexokinase and phosphofructokinase enzyme activities were significantly reduced (36.46, 57.85, 32.64, 54.68 and 24.59 %, respectively); glycogen and triglyceride levels were significantly increased (42.17 and 120.36 %). We conclude that D. suzukii is typical of short-day diapause species within a certain photoperiod range. This information might contribute to a more fundamental understanding of adult reproductive diapause for this important pest.