Dacus dorsalis: Vapor Heat Treatment in Papayas1

Abstract

Heating of 4-h-old eggs and nearly mature 3rd-instars of the oriental fruit fly in water in the laboratory indicated that minimum periods for 100% kill were 60, 14, 3, 1, or ¼ min at constant 43.3, 46.1, 48.9, 51.7 or 54.4°C, respectively, for 4-h-old eggs and 65, 18, 5, or ¼ min at constant 43.3, 46.1, 48.9, and 54.4°C, respectively, for 3rd instars. None of 262,555 eggs, 1st, 2nd, and 3rd-instars located in 1095 heavily infested papayas at depths of 0–2.0 cm survived commercial-type vapor heat treatment. Treatment consisted of an average 11-h approach period to raise the mean temperature of the fruit from 23.3° to 44.4°C, and then holding the fruit at a constant mean temperature of 44.4°C for 8-¾h.