Survey of pathogens and parasitoids in late instar Lymantria dispar larval populations in sardinia, Italy

Gypsy moth (Lymantria dispar L.) larvae were collected in 20 oak stands in Sardinia to evaluate mortality factors. Collected larvaewere reared in the laboratory on artificial diet until they died or pupated. Larval mortality ranged from 17.5 to 100%. Parasitoidsthat killed larvae and pupae were identified and the remaining larvae were evaluated for presence of pathogens. Of the five parasitoids species recorded, the dipteran tachinid Blepharipa pratensis Meigen was the most frequently observed and caused up to 57.5% mortality. The viral pathogen LdMNPV caused mortality up to 37.5%. We recorded the presence of the fungus Beauveria bassiana (Balsamo-Crivelli) Vuillemin as well as the microsporidium Nosema portugal Maddox et Vavra, which was previously identified as Nosema lymantriae Weiser. The fungal entomopathogen Entomophaga maimaiga Humber, Shimazu et Soper was not collected from the host populations surveyed. We suggest that an inoculative introduction of this pathogen into Sardinia could potentially reduce the need to control gypsy moth populations with microbial pesticides, which are expensive to apply and are toxic to many non-target organisms.