PSEUDOMETAGEA SCHWARZII (ASHM.) (EUCHARITIDAE: HYMENOPTERA), A PARASITE OF LASIUS NEONIGER EMERY (FORMICIDAE: HYMENOPTERA)

Abstract

In 1960 and 1961, studies were made on Pseudometagea schwarzii (Ashm.), a parasite of Lasius neoniger Emery in southern Ontario. The eggs are deposited in vegetation surrounding the ant nest and the first instar larvae (planidia) transfer to the ant Larvae by attaching themselves to the worker ants. The larvae overwinter as internal parasites but complete their development as external parasites after the host has pupated in the spring. The adults emerge in June and oviposit immediately.The adult parasites usually do not leave the area of the nest and, through the foraging activities of the ants, the planidia are returned to the colony that was originally parasitized. Hence the population is intensified and localized. Ninety percent parasitism of the overwintering brood may occur. The possible effects of this parasite on the host population are discussed.