Residual Effectiveness of Foliar Sprays Against the Oriental Fruit Fly, Melon Fly, and Mediterranean Fruit Fly

Insecticides were evaluated in Hawaii between 1952 and 1960 as foliar sprays for control of the oriental fruit fly, Dacus dorsalis Hendel; the melon fly. D. cucurbitae Coquillett; and the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). Twigs bearing guava tree foliage were sprayed to runoff with an insecticide, allowed to weather for 1-16 days during dry or rainy weather, and then exposed for 24 hours to oriental fruit flies alone or in combination with melon flies and Mediterranean fruit flies. Comparisons of the mortalities obtained with 37 insecticides after 1, 2, 4, 8, and 16 days’ weathering indicated that fenthion, parathion, dieldrin, dimethoate, azinphosmethyl, malathion, DDT, ethion, isodrin, and methoxychlor at appropriate rates were most effective; however parathion, malathion, and azinphosmethyl, though effective in dry periods, were susceptible to loss from rainfall. Lindane, toxaphene, Perthane® (a mixture of 1,1-dichloro-2,2-bis ( p -ethylphenyl) ethane (95%) and related reaction products (5%)), diazinon, trichlorfon, and naled were among the compounds having poor residual effectiveness. The melon fly was more tolerant of Chlorthion® ( O -(3-chloro-4-nitrophenyl) O, O -dimethyl phosphorothioate) and DDT but more susceptible to trichlorfon, carbaryl, and endosulfan than the oriental fruit fly. The Mediterranean fruit fly was more susceptible than the oriental fruit fly to Bay 22408 ( O, O -diethyl phosphorothioate O ester with N -hydroxynaphthalimide), trichlorfon, carbaryl, and endosulfan.