Impact of tachinid parasitoids of gypsy moth (Lymantria dispar) after the natural spreading and introduction of fungal pathogen Entomophaga maimaiga in Serbia

In 2013, parasitoids of Tachinidaefamily of Lymantria dispar(L.) were studied in 12 forest stands in four regions in Serbia. Biological material for the investigations was collected in mixed oak and beechstands in which gypsy moth increased in number and where entomopathogenic fungus Entomophaga maimaigaHumber, Shimazu & Soper was established or introduced. A total of 1117 larvae and 814 pupaeof L. dispar were collected and analyzed. Host mortality caused by tachinids in different localities varied between 0.7% and 37.1%. A total of 274 tachinid larvae and pupaewere reared from gypsy moth larvae and pupae. Out of these, 266 died as pupae, resulting in an extremely high overall mortality of 97.1%. Only eight tachinid adult specimens of 3 species ( Compsilura concinnata, Exorista larvarumand Carceliagnava) emerged from tachinid pupae. E. maimaiga azygosporeswere observed on the surface of 69.5% but not in internal tissues of the dead pupae. The results of this study support the hypothesis of competition between natural enemies of the pest.