Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2006
Publication Date: 8/1/2009
Citation: Cancino, J., Ruiz, L., Sivinski, J.M., Galvez, F.O., Aluja, M. 2009. Rearing of five hymenopterous larval-prepupal (Braconidae,Figitidae) and three pupal (Diapriidae,Chalcidoidea,Eurytomidae)native parasitoids of the genus Anastrepha(Diptera:Tephritidae) on irradiated A.ludens larvae and pupae. Biocontrol Science and Technology. 19:193-209. Interpretive Summary: Interpretive Summary Fruit flies, such as the West Indian and Caribbean fruit flies, are invasive pests that not only destroy crops but are the cause of trade barriers where ever they occur. One means of preventing such invasions is to suppress fruit fly populations in countries neighboring the USA. Scientists at the Center for Medical, Agricultural and Veterinary Entomology (Gainesville, Florida) in collaboration with colleagues at the Instituto de Ecologia (Xalapa, Veracruz, Mexico) have explored the possibility of pest control through mass-rearing and releasing parasitoids that attack fruit flies. Parasitoids that can develop in irradiated hosts, that will not themselves mature, are easy to release without the danger of also accidentally releasing fertile fruit flies. Eight species of Mexican larval-prepupal and pupal fruit fly parasitoids which have been recently domesticated and colonized were reared on irradiated larvae and pupae, and the optimal irradiation doses determined. In the future these species will be candidates for area-wide control programs
Technical Abstract: Abstract The aim of this study was to ascertain if eight species of native larval-prepupal and pupal Anastrepha (Diptera: Tephritidae) parasitoids which have been recently domesticated and colonized [Aluja et al. this volume] could be reared on irradiated larvae and pupae and if such was the case, determine the optimal irradiation dose so that only adult parasitoids (not flies) would emerge. The species considered were: Doryctobracon crawfordi, Utetes anastrephae, Opius hirtus (all larval-prepupal braconids), Aganaspis pelleranoi, Odontosema anastrephae (both larval-prepupal figitids), Coptera haywardi, Eurytoma sivinskii and Dirhinus sp. (diapriid, eurytomid and chalcidoid pupal parasitoids). Eight day-old A. ludens larvae or three day-old A. ludens pupae were irradiated with 0, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60 and 70 Gy under free oxygen and then subjected to parasitoid attack. Emergence of the unparasitized host was completely halted at 15-20 Gy but such was not the case with the three braconid parasitoids that emerged even if subjected to doses as high as 70 Gy. In the case of the figitids, both emergence of the adult parasitoids and their host was completely halted at 20 Gy. Some emergence was recorded at 5 and 10 Gy but at this irradiation dose, fly adults also emerged rendering the fly/parasitoid separation procedures impractical. Finally, in the case of the pupal parasitoids, A. ludens adults emerged from unparasitized pupae irradiated at 15 Gy. Beyond this dose, only parasitoids emerged. Of the three pupal parasitoid species tested, C. haywardi (the only endoparasitoid) was slightly more susceptible to high irradiation doses. With the exception of the eucoilid larval-prepupal parasitoids, irradiation did not negatively affect adult longevity or fecundity. Our results show that parasitoid mass rearing with irradiated hosts is technically feasible.