SPERM TRANSFER BY GYPSY MOTHS (LEPIDOPTERA, LYMANTRIIDAE) FROM IRRADIATED MALES - IMPLICATION FOR CONTROL BY INHERITED STERILITY

When gypsy moths, Lymantria dispar (L.), whose male parent received 6, 8, or 10 krad of gamma irradiation were mated with untreated females, fewer transferred sperm than progeny of untreated males. Further, the quantity of eupyrene sperm transferred by offspring of irradiated mal es was less than that of progeny of untreated males. The effect was de pendent upon dose. In untreated insects, fecundity as determined by we ight of the egg mass was dependent upon quantity of eupyrene sperm in the spermatheca. But when the male parent was irradiated, fecundity of his daughters or of untreated females mated with the sons was less th an that of untreated adults regardless of the quantity of eupyrene spe rm. Females from 10-krad-treated males took longer than untreated fema les to begin copulating. These results suggest that insects from irrad iated males released for suppression of a population may not be suffic iently competitive with feral insects.