Herina nigrina

A relatively large picture-winged fly (to 6 mm) with a unique wing pattern comprised of a dark tip, and darkened outer crossvein and an L-shaped mark that occupies the costal cells but then extends at a right angle to encompass the inner crossvein. There is no substantial basal band below the costal cell in contrast to H. lugubris. Like most other Herina species, the head has silver stripes beside the eyes, and a reddish face and frontal stripe.

Herina lugubris

Good photos showing wing pattern rerquired. 

Dry calcareous sites with sparse vegetation and brownfield sites (especially quarries). Often occurs alongside H. lugubris.

Summer

Fairly frequent in southern England. 

Uncommon, local.