Features of the Far Eastern Gypsy Moth (Lymantria dispar L.) Population Outbreak

Abstract

Data characterizing the gypsy moth Lymantria dispar population in the eruptive phase in the Far East territory in 2008 are presented. The death of insects based on biotic factors (parasitoids and nuclear polyhedrosis virus) has been studied; the sex ratio, weights of male and female pupae, and female fecundity have been determined. It is shown that nucleopolyhedrovirus is the main cause of death for caterpillars and inhibits the eruptive phase of abundance. It appears that no gypsy moth caterpillars die from entomopathogenic fungi. A strong decrease in the proportion of females is partially mediated by sex-specific parasitism and the moderate fecundity of females, and a high rate of virus-induced mortality is responsible for the fast decline in L. dispar population density in the Far East.