Toxicity of Neem (Azadirachta indica) Seed Cake to Larvae of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera: Tephritidae), and Its Parasitoid, Diachasmimorpha longicaudata (Hymenoptera: Braconidae)

The objective of this study was to evaluate the interaction of Diachasmimorpha longicaudata (Ashmead) parasitism and the toxicity of neem seed cake (NSC) on survival of Ceratitis capitata (Wiedemann), the Mediterranean fruit fly (medfly). Groups of 1600 – 1700 third instar C. capitata larvae were each wrapped in organdy cloth (“unit of parasitism”) and exposed to approximately 500 couples of sexually mature D. longicaudata parasitoids (5-d old) for one hour. C. capitata larvae exposed or not to parasitism were transferred to plastic cups containing vermiculite with different proportions of neem seed cake (NSC): 0% NSC (control), 5% NSC, 10% NSC, 15% NSC, 20% NSC, 25% NSC, 30% NSC. Both NSC and the parasitism caused larval/pupal mortality and reduced the emergence of C. capitata flies. NSC affected parasitoid emergence negatively. The effect of parasitism coupled to NSC did not provide greater reduction in the medfly emergence than when parasitism was used alone. However, each of these 2 methods affect a different life stage of medfly, larvae and pupae, respectively, and their joint use may increase the probability of controlling medfly populations in field.