HOST CORN-EARWORM (LEPIDOPTERA, NOCTUIDAE) REARED ON MERIDIC DIET CONTAINING SILKS FROM A RESISTANT CORN GENOTYPE ON ARCHYTAS-MARMORATUS (DIPTERA, TACHINIDAE) AND ICHNEUMON-PROMISSORIUS (HYMENOPTERA, ICHNEUMONIDAE)

Larvae of Helicoverpa zea (Boddie) fed on a meridic diet containing si lks of a resistant com genotype, 'Zapalote Chico 2451# (PC3)', were ex amined as suitable hosts for a larval-pupal parasitoid, Archytas marmo ratus (Townsend), and a pupal parasitoid, Ichneumon promissorius (Eric h). Host pupal weight, parasitoid weight, and developmental time were significantly reduced when host larvae were reared on a diet containin g resistant silks compared with diet without resistant silks. Weight o f A. marmoratus was strongly correlated with host weight for both host diets. Parasitoid developmental time for both parasitoids was also co rrelated with host pupal weight for hosts fed on a diet containing res istant silks. Fecundity of both parasitoids was not affected by host d iet. Adult longevity of I. promissorius was significantly reduced when reared from hosts fed the diet containing resistant silks compared wi th hosts reared on the diet without resistant silks. Longevity of fema le A. marmoratus was not affected by host diet, but male A. marmoratus lived longer when reared from hosts fed the resistant diet. Despite a few negative effects (lower percentage emergence of A. marmoratus) of a resistant host diet on the parasitoids, these strategies could be c ompatible because the negative effects did not result in lower parasit oid fecundity or increased parasitoid developmental time.