Gasterocercus depressirostris depressirostris (Fabricius) (Coleoptera, Curculionidae) - a new xylophagous pest of Quercus cerris L. and a new robber fly (Diptera, Asilidae) predator on it in Bulgaria.

The insect pest complex of Turkey oak (Quercus cerris L.) was studied in the field protective forest belts planted on the territory of the State Forest Enterprise Dobrich in south Dobrudzha, north-eastern Bulgaria. Stem cuttings attacked by xylophagous insect pests were collected on 13 March 2025 in the land of Pobeda and Metodievo Villages. The samples were reared in photoeclectors at room temperature (18-22°C). During the period from 24 June to 24 July 2025, the oak weevil Gasterocercus depressirostris depressirostris (Fabricius, 1792) (Coleoptera, Curculionidae) was reared for the first time from Quercus cerris L. in Bulgaria. Additionally, a new species for Bulgaria's asilid fauna, Pogonosoma minus Loew, 1869 (Diptera, Asilidae), was observed developing in the larval galleries of the pest. The trophic relationship between the predatory robber fly and the weevil prey was previously unknown and is recorded for the first time in this study.