New localities of Entomophaga maimaiga and suppressing of Lymantria dispar calamity in northwest Bulgaria.
In 2014, strong attacks caused by gypsy moth (Lymantria dispar) were registered on 15 394 ha forest area in Northwestern Bulgaria on the territory of State Forestries Vidin, Belogradchik, Chuprene and Berkovitsa. Due to the rainy spring of this year and the favourable conditions for the development of introduced entomopathogenic fungus Entomophaga maimaiga, 12 attacked forest stands were investigated for establishment of gypsy moth epizootics caused by the pathogen. In 10 stands many dead late-instar larvae with typical symptoms of E. maimaiga were observed on tree trunks. Microscopic analysis showed that all dead larvae were infected by E. maimaiga. It is the first record of the pathogen in the region of Vidin, Belogradchik and Chuprene. In two localities mixed infections of gypsy moth caused by E. maimaiga and Lymantria dispar multicapsid nuclear polyhedrosis virus (LdMN PV) were established. The massive epizootic of gypsy moth by E. maimaiga suppressed the calamity and accumulated inoculums will regulate population density of the pest in the region.