SOME INTERACTIONS OF TWO BACULOVIRUSES OF THE DOUGLAS-FIR TUSSOCK MOTH (LEPIDOPTERA: LYMANTRIIDAE)

Abstract

AbstractTwo nuclear polyhedrosis viruses were fed to larvae of the Douglas-fir tussock moth, Orgyia pseudotsugata. Mixtures of the two viruses in varying proportions and separate doses of the two with a varying time interval between were administered. Larvae dying of polyhedrosis were examined to determine the proportions of the two viruses found in the bodies of the insects. The multicapsid virus (BV) showed a tendency to predominate over the unicapsid virus (SV), particularly in massive doses. In small doses, SV appeared in mixed infections even when the proportion of SV in the infective dose was small. When BV was administered 24 h in advance of SV, the development of SV was inhibited completely. At shorter intervals of time between doses, mixed infections occurred.