Bernard Castelein / Fly (Physocephala rufipes), Klein Schietveld, Brasschaat, Belgium. August

Kim Taylor / Thick-headed fly (Physocephala furcillata) on Eryingium. Surrey, England, UK, August.

Nick Upton / Thick-headed fly (Physocephala rufipes), a parasite of bees, feeding on Japanese mock orange flowers (Pittosporum tobira), Lesbos/ Lesvos, Greece, May.

Rod Williams / Thick headed fly (Physocephala rufipes) feeding on Black knapweed (Centaurea nigra) flower, Sutcliffe Park, Eltham, London, England, June.

Stephen Dalton / Thick headed fly (Physocephala nigra) in flight, controlled conditions.

Premaphotos / Thick-headed fly (Physocephala rufipes) mating pair, UK

Doug Wechsler / Thick-headed fly (Physocephala tibialis) a wasp mimic, resting on leaf, Pennsylvania, USA. September.