Cold disinfestation of citrus (Citrus spp.) for Mediterranean fruit fly (Ceratitis capitata) and Queensland fruit fly (Bactrocera tryoni) (Diptera: Tephritidae)

Abstract

Cold treatment of citrus (Citrus spp.) fruits to achieve quarantine levels of disinfestation of fruit flies is a viable alternative to methyl bromide fumigation for export purposes. A series of trials, using standard bioassay procedures followed by large‐scale export tests, were conducted on five citrus cultivars at 2°C and 3°C against the Mediterranean fruit fly (MFF) (Ceratitis capitata) and the Queensland fruit fly (QFF) (Bactrocera tryoni). The exposure periods required to achieve complete mortality in >30 000 insects varied with fruit fly species and cultivar. For MFF, control at 2°C was obtained in 16 days in lemons (Citrus limon) and 18 days in oranges (Citrus sinensis) and mandarins (Citrus reticulata); whereas at 3°C, 18 days were required in lemons and 20 days in oranges and mandarins. For QFF, control was obtained in 14 days in lemons and 16 days in oranges and mandarins at both 2°C and 3°C. The application of these results will provide more flexibility for the citrus industry in satisfying quarantine treatments.