Sicus ferrugineus · lenktapilvė musė

EN · ferruginous bee-grabber
DE · Gemeine Breitstirnblasenkopffliege
PL · ślipień trzmielowiec

https://en.wikipedia.org/wiki/Sicus_ferrugineus
Adults can be encountered from May through September, feeding on nectar or pollen. Their larvae are endoparasites of bumble bees of the genus Bombus. They pupate and overwinter in their victims.
1854