Hot-Air Quarantine Treatment for ‘Marsh’ White Grapefruit Infested with Caribbean Fruit Fly (Diptera: Tephritidae)

Abstract

A single-stage hot-air quarantine treatment disinfested Florida-grown ‘Marsh’ white grapefruit, Citrus paradise Macfadyen, of Caribbean fruit fly, Anastrepha Suspensa (Loew), eggs and larvae without damaging the fruit. Treating infested grapefruits with 48 ± 0.3°C forced air for 63, 105, 135, and 195 min, when center pulp temperatures were 28-29, 36-37, 40-41, and 44-45°C, respectively, reduced the number of surviving puparia that developed from treated larvae. Probit analysis estimated the exposure time needed to reach 99.9968% (probit 9) mortality as 202 min (lower and upper FL were 170 and 271 min, respectively) when the mean center pulp temperature was ≥45.7°C. A large-scale confirmatory test resulted in no survivors when 115,037 A. suspense larvae in 3,480 infested grapefruits were heated with 48 ± 0.3°e forced air at an average 0.75 m3/s air flow rate until the center pulp temperature was ≥ 44°C, which required ≥150 min of heating.