Pathogenicity and Sporulation of Entomophaga maimaiga HUMBER, SHIMAZU, SOPER and HAJEK (Entomophthorales : Entomophthoraceae) on Larvae of the Gypsy Moth, Lymantria dispar L. (Lepidoptera : Lymantriidae)

Abstract

Pathogenicity, spore type and number of conidia of Entomophaga maimaiga produced by infected gypsy moth larvae were investigated. This fungus was highly pathogenic to gypsy moth larvae older than 2nd instar at temperatures between 15° and 25°C. The 3rd and 4th instar larvae were the most susceptible to this fungus. The rate of resting spore formation was higher in older instar larvae, however, conidia were also often produced on these cadavers. The rate of resting spore formers was not affected by the temperature. Almost 100% RH was necessary for the infection of conidia of this fungus. The number of discharged conidia from a cadaver was generally higher on older larvae reared at 15° and 20°C.