Effects of temperature on the reproduction and development of Drosophila suzukii (Diptera: Drosophilidae)

The objective of this study was to elucidate how temperature affects the reproduction and development of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), an emerging major pest of blueberry in Japan. Although extensive studies of the biology of this pest have been carried out, the effects of temperature on its reproduction and development remain unknown. We found that when adults mated at 31 A degrees C for 4 days, none of the eggs hatched. Female oviposition and egg hatching rate were also reduced as temperature increased during the oviposition period. When D. suzukii larvae developed above 31 A degrees C, pupation and adult eclosion were abolished. According to field observations, adult D. suzukii ceased to appear from the end of July 2010, when the average temperature exceeded 28 A degrees C or when the temperature within a day exceeded 33 A degrees C for 8 h or more. Experiments in which the mating temperature fluctuated within a day revealed that both the number of eggs oviposited and their hatch rate were significantly suppressed when the daily temperature regime during mating was either 31 A degrees C for 12 h/25 A degrees C for 12 h or 33 A degrees C for 8 h/25 A degrees C for 16 h, relative to the values at 25 A degrees C for 24 h.