Response of Three Hymenopteran Parasitoids Introduced for Fruit Fly Control to a Gall-Forming Tephritid, Procecidochares alani (Diptera: Tephritidae)

The response of three larval–pupal parasitoids, Diachasmimorpha longicaudata (Ashmead), Diachasmimorpha tryoni (Cameron), and Tetrastichus giffardianus Silvestri, to the Hamakua pamakani gall fly, Procecidochares alani L., was determined in the laboratory. We also observed responses of these parasitoids to their normal rearing hosts, Bactrocera dorsalis (Hendel) andCeratitis capitata (Weidemann).D. tryoni landed on pamakani galls or on dishes containing P. alani larvae as frequently as on dishes containing C. capitata. In contrast, D. longicaudata only rarely landed on the galls. D. tryoni and D. longicaudata oviposited in galls in fewer than 1% of our observations. D. longicaudata probed P. alani larvae as frequently as B. dorsalis larvae, but no parasitoid offspring were observed. D. tryoni oviposited more frequently in C. capitata than P. alani. No D. tryoni developed in P. alani larvae. T. giffardianus landed on pamakani galls and P. alani larvae more frequently than any other host substrate. In contrast, T. giffardianus entered galls with artificially opened windows one time in 10 observations. We observed 12% parasitism of P. alani larvae dissected from the galls and 20% of parasitism P. alani in the windowed galls. We discuss the implications of our results for future augmentative or classical biological control studies. r 1997