Wikipedia
Herina (fly)
Herina is a genus of flies in the family Ulidiidae. It is possibly the largest genus in the family.
It is a genus of distinctive, small to medium-sized, dark species about 3.5-5.5 mm long, with patterned wings. The head is variably yellowish, reddish, or darkened, whilst the body is either shining black or black dusted with grey. Many are found in marshland or calcareous grassland locations and in coastal wetlands.