Penetration into caterpillar cells of virus-like particles injected during oviposition by parasitoid ichneumonid wasps

Abstract

Particles originating from the ovarial calyx epithelium of 2 different species of ichneumonid wasp [Hypogaster fugitivus fugitivus and Campoletis sonorensis] were injected into host caterpillars [Malacosoma americana and Heliothis virescens] during oviposition. At 1 3/4 h post oviposition, many calyx fluid particles were associated with or had penetrated through the basement membranes surrounding various tissues. Shortly thereafter, apparently intact particle nucleocapsids were observed in both cytoplasm and nucleus of host cells. An unusual tubular protrusion of the viral envelope appeared to be involved in penetration of basement membranes and/or entry of nucleocapsids into host cells.