Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/1996
Publication Date: N/A
Interpretive Summary: To develop safe and effective alternatives to the use of environmentally hazardous pesticides, Scientists at the Insect Attractants, Behavior, and Basic Biology Research Laboratory in Gainesville, Florida are developing means of biological control. Currently, rearing the beneficial insect, Microplitis, on the typical host species, Corn earworm or Tobacco budworm, for large-scale pilot tests are cost prohibitive. Because of th potential use of Microplitis as a biological agent in pest management programs, research has focused on finding an acceptable alternate host that is less expensive to rear. Parasitism by Microplitis in the Greater wax moth was significantly improved by the application of a host-seeking stimulant in combination with concentrated insect blood, but the rate of adult parasitoid emergence was not increased by the addition of nutrient supplements. Therefore, although Microplitis can be reared on the alternate host, the Greater wax moth, the rate of growth and emergence was insufficient for this approach to be used on a practical basis, and additional research on parasite growth factors is thus required.
Technical Abstract: The effect of various diet supplements on the development of Microplitis croceipes in an atypical host, Galleria mellonella (Linnaeus), was evaluated, as were ovipositional responses to various factors. Female parasitoids were exposed to fifth instar G. mellonella treated with combinations of frass, host- seeking stimulant (HSS,13-methylhentriacontane), hemolymph, and freeze dryed hemolymph from Helicoverpa zea (Boddie). There were no significant differences between hemolymph and frass + hemolymph treatments. The 1% and 10% HSS treatments stimulated oviposition to 50.0% and 46.7%, respectively. Most effective combinations were 1% and 10% concentrations of HSS with concentrated hemolymph which stimulated oviposition to 70.0% and 92.2%, respectively. These values were comparable to the oviposition rate in the typical host, H. zea. Various diet supplements were added to the G. mellonella diet to 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 HSS and concentrated hemolymph, but the rate of adult parasitoid emergence was not increased by the addition of nutrient supplements to the host diet.