Cold Response of the Mediterranean Fruit Fly () on a Lab Diet.

Cold treatment at 0.0 °C with different exposure durations (0⁻12 days) was applied to the Mediterranean fruit fly (Wiedemann) fed on a lab diet. The examined developmental stages were early eggs (<6 h), late eggs (>42 h), first instar, second instar and third instar larvae. Pupation, adult emergence and sex ratios of survived flies were investigated to study the responses to this low temperature treatment. Our results showed that exposure time at low temperature has a clear effect on pupation and adult emergence. Based on pupation ratios, the first and third instar are the most cold tolerant stages, with LT99 = 7.3 for both of them. Cold tolerance at both stages are very close and no significant differences were detected. There were no significant differences on sex ratios among different stages after treatment. This study improves our understanding of responses to cold treatment, which may assist in the improvement of the current treatment strategies to control this destructive horticulture pest species.