closeup on the forest four colored cuckoo-bumblebee, bombus sylvestris on a pink walflower, erysimum cheiri

arthropoda bee bombus species sylvestris cuckoo bumblebee ecology forest hymenoptera insect nature psithyrus animal biology cleptoparasite closeup entomology fourcoloured invertebrate macro male outdoors parasite pollinator single solitary wild wildlife four colored pink walflower erysimum cheiri garden