Isolation and characterization of Entomophaga maimaiga sp. nov., a fungal pathogen of gypsy moth, Lymantria dispar, from Japan

Abstract

A Japanese zygomycete pathogen from the gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), is described as Entomophaga maimaiga sp. nov. (Entomophthorales: Entomophthoraceae). This fungus belongs to the Entomophaga aulicae species complex. Isolates from the E. aulicae species complex were tested for infectivity and pathogenicity toward larvae of the gypsy moth, and only those isolates from gypsy moths were pathogenic to gypsy moth larvae. Electrophoretic studies of isoenzymes indicated that the Japanese gypsy moth isolates differed from other Japanese and North American strains of the E. aulicae species complex. Among the isolates of E. maimaiga from Japan, ARSEF 1400 appeared most promising for biological control use; it caused 90–95% mortality in third instar larvae after an average of 5.2 days and can be cultured in both protoplast and mycelial vegetative stages. In host range trials, ARSEF 1400 infected only a few of the lepidopteran species tested. Among these alternate hosts, mortality was the greatest (92.5%) for the Douglas-fir tussock moth, Orgyia pseudotsugata, another economically important lymantriid.