An 18-day, 3 °C cold treatment effectively kills Ceratitis capitata (Diptera: Tephritidae) in kiwifruit (Actinidia spp.).

ABSTRACT

A series of experiments were carried out to develop a phytosanitary disinfestation protocol to kill Ceratitis capitata (Weidemann) (Mediterranean fruit fly, Diptera Tephritidae) in 'Hayward' kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang and A.R. Ferguson) and 'Zesy002' kiwifruit (Actinidia chinensis Planch.). Experiments on 4 immature life stages (eggs and 3 larval instars) with treatment durations of between 5 and 18 days showed that third instars were the most tolerant to temperatures around 3 °C, with the lethal time to 99.9968% (probit 9) mortality (LT99.9968) estimated to be 17.3 days (95% confidence interval (CI) 16.4-18.2). Larvae reared and treated in 'Zesy002' were significantly more susceptible to cold treatment than those reared in 'Hayward'. A large-scale trial testing a disinfestation protocol of 3 ±â€…0.5 °C for 18 days treated over 500,000 third-instar C. capitata with no survivors. These results demonstrate that a cold treatment of 3.5 °C or below for 18 days induces C. capitata mortality in kiwifruit at a rate that exceeds 99.9968% with a degree of confidence greater than 99%.