closeup on the forest or four-coloured cuckoo bee,bombus sylvestris, sitting on a purple knapweed flower

arthropoda arthropod bee bombus vestalis cuckoo bumblebee hymenoptera insect nature psithyrus vestal animal biology cleptoparasite closeup entomology invertebrate macro outdoors parasite pollinator single solitary wild wildlife natural forest fourcoloured sylvestris sitting purple knapweed flower four-coloured