Transmission of Virus in Tent Caterpillar Populations

Abstract

The transmission of nuclear polyhedrosis virus in populations of the forest tent caterpillar, Malacosoma disstria (Hübner), was studied in Sudbury district, Ontario. Virus was transmitted from generation to generation by infected adults. Their progeny died from virus disease during the second and third larval instars. Adult flies of Sarcophaga aldrichi Parker, a dipterous parasite, were attracted to these dead, diseased larvae, became contaminated with virus, and spread the virus to foliage on which healthy larvae were feeding. The importance of these disseminating agents in the development of virus epizootics is discussed.