New records and impact of tachinid parasitoids of Thaumetopoeapityocampa (Lepidoptera: Notodontidae) in Bulgaria

The impact of larval and pupal parasitoids of Thaumetopoea pityocampa was studied in laboratory conditions, during the period February-October 2021. The material, 138 hibernating caterpillars of summer form and 415 larvae of winter form intercepted during processions, was collected from two localities – Dobrostan Vill. and Gotse Delchev, respectively. In the land of Kovil Vill., which is occupied by the winter form, the winter nests of T. pityocampa were checked for infection by parasitoids. In this study, all isolated parasitoids belong to the family Tachinidae. As a result, 3 species – Phryxe vulgaris (Fallén, 1810), Compsilura concinnata (Meigen, 1824) and Bothria frontosa (Meigen, 1824) were found to parasitized T. pityocampa. A relatively high parasitism rate of T. pityocampa winter formby tachinids was observed – 21%, of which P. vulgaris parasitized 15.2% of the sample. Conversely, the parasitism rate of T. pityocampa summer form is low – 5%, in which C. concinnata parasitized 1.4% from the sample. Two puparia of B. frontosa were collected fromlarval winter nests of T. pityocampa in the region of Kovil Vill. This is the first record of the Notodontidae family as a host of Bothria frontosa. A complete up-to-date list of trophic connections of T. pityocampa with tachinid parasitoids, reported in Bulgarian and international publications is provided, as well as their impact on pest populations.