ESTABLISHMENT IN MAINE, NOVA SCOTIA, AND NEW BRUNSWICK OF OLESICAMPE BENEFACTOR (HYMENOPTERA: ICHNEUMONIDAE), AN INTRODUCED ICHNEUMONID PARASITE OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

Abstract

AbstractSmall numbers (147–388) of Olesicampe benefactor Hinz, a European ichneumonid parasite of the larch sawfly, Pristiphora erichsonii (Htg.), were released in Maine, Nova Scotia, and New Brunswick in 1967. The parasite became established and has survived through two winters at five release points, and three winters on three release sites; on two sites the continued survival of the parasites is unconfirmed because of the collapse of the host population. O. benefactor is known to disperse slowly and even if it is successful in controlling the sawfly in the release areas, control over large areas may require releases at many locations.The subject of the range of host densities at which parasite releases should be made to ensure the greatest parasite production per parasite released, and hence the greatest chance of successful establishment, is discussed.