Drone Fly/Hoverfly Eristalis tenax/pertinax/sp.

The Drone Fly is a Honey Bee mimic hoverfly named after the male honey bee. The name is sometimes applied only to the largest, darkest of the Eristalis Honey Bee mimic species - Eristalis tenax, sometimes to the two largest and darkest, E. tenax and E. pertinax, or to the whole family of Eristalis species (including in the UK E. horticola, E. arbustorum, E. interruptus, E. nemorum and others).

The Drone Fly above, Eristalis tenax, is the largest and usually the darkest Drone Fly. However, abdomen patterns and darkness vary considerably and almost any of the Eristalis species, especially the females, can be completely or nearly black. Tenax has completely black hind legs.

Tenax also has thicker, hairier back thighs to resemble a honey bee's pollen basket - not something the male drone bee would have. It is hard to see the black hind leg when covered in pollen.

Sometimes the Drone Flies have bold, white lines between abdominal segments - on both males and females (Is this only for Eristalis arbustorum?)

Usually there are no white lines

Despite the hairy "pollen basket" back thigh, this hoverfly is thought to be Eristalis pertinax . . .

because of the yellow area on the hind legs.