NOTES ON MATING BEHAVIOR AND OVIPOSITION OF CHRYSOCHARIS LARICINELLAE (HYMENOPTERA: EULOPHIDAE), A PARASITE OF THE LARCH CASEBEARER (COLEOPHORA LARICELLA)

Abstract

Chrysocharis laricinellae (Ratz.) mated readily in the laboratory when several individuals of both sexes were held together in a vial. The courtship dance performed by the male is described. Parasite females develop mature eggs 3 days after emergence and are apparently capable of resorbing the eggs if hosts are not available, and to produce new ones after host-feeding. Storage of eggs in the ovary for 5 months at 55°F and sterility (phasic castration) of certain individuals is reported. Longevity of egg-laying females at 75°F was about 1 month less than that of parasites that had been denied contact with hosts. Odor apparently plays little or no role in the location of the larch casebearer larvae by C. laricinellae, but chemical surface stimuli seem to exist on the surface of a mine or case of Coleophora laricella (Hbn.). The parasite is also stimulated by vibrations of the host in its case. The oviposition and host-feeding pattern of C. laricinellae is described. Host-feeding on fourth-instar larvae of the larch casebearer contributed little to host mortality.