Submitted to: Entomological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 8/18/1997
Publication Date: N/A
Technical Abstract: Whole venom of the ectoparasitoid Euplectrus comstockii (Hymenoptera: Eulophidae) arrests larval-larval apolysis and ecdysis when injected into the hemocoel of its lepidopteran hosts. Arrestment activity found within the hemolymph of parasitized Trichoplusia ni arrested ecdysis only, and that activity diminished from 100% at the time of parasitism, to less than 5% by 20 hours post-parasitism. When venom is incubated with hemolymph outside the host, ecdysis-arrestment activity diminished only slightly from 100% to 80% over this same time period. Antibodies to both whole venom and the N-terminus of an ecdysis-arresting protein from the venom were used to visualize the fate of venom proteins. The decline in the presence of the ecdysis-arresting protein was similar to the decline in ecdysis-arrestment activity found in the hemolymph of parasitized T. ni, suggesting that this protein is, in part, responsible for the venom's ability to arrest larval-larval ecdysis.