none Galleria mellonella; HYMENOPTERAN-PARASITES; Microplitis croceipes; Parasitism of atypical host, parasite mass rearing significance Microplitis croceipes; REARING-TECHNIQUES; Mass rearing using atypical lepidopteran host; LEPIDOPTERAN-HOSTS; Galleria mellonella; Parasitism of atypical host, parasite mass rearing significance The effect of various diet supplements on the development of Microplitis croceipes in an atypical host, Galleria mellonella (Linnaeus), were evaluated, as were ovipositional responses to various factors. Female parasitoids were exposed to fifth instar G. mellonella in Petri dishes containing the following treatments either separately or in combination: a) Helicoverpa zea (Boddie) frass, b) 1% and 10% solutions of a host-seeking stimulant (13-methylhentriacontane), c) H. zea hemolymph, and d) H. zea hemolymph concentrated by freeze-drying. There were no significant differences between hemolymph and frass + hemolymph treatments. The host-seeking stimulant alone also stimulated oviposition. The most effective combination was host-seeking stimulant and concentrated hemolymph which induced oviposition rates comparable to that in the typical host, H. zea. Various diet supplements did not improve the development and emergence of M. croceipes. We conclude that oviposition by M. croceipes in the atypical host, G. mellonella, was significantly improved by the application of host-seeking stimulant and concentrated hemolymph, but the rate of adult parasitoid emergence was not increased by the addition of nutrient supplements to the host diet.