Sialis nigripes
Sialis nigripes is the rarest of the three Sialis species in the British Isles and the least known about. There is little known about its habitat requirements and its life history. It is dark brown to black in colour and has four membranous wings all unpatterned, all uniformly brown in colour with dark veins. The wings are held roof-like over abdomen. Its antennae are shorter than its forewings. Sialis fulginosa has a body length of 10mm and a wingspan of 27-34mm.
Widespread but local in England, Wales, Scotland and Ireland. It is an underrecorded species
To identify to species level you must examine the genitalia.
Male genitalia: Tip of abdomen hinged (in vertical plane) opening up to reveal genital structures. Genital structures as in figure, Subgenital plate much shorter than the tip of the abdomen.
Female genitalia: Tip of abdomen is rounded, without an opening. When viewed on the underside (ventral view) the Anal plates with small “eye-like” tips.
Lakes and rivers, most records from calcareous waters. Larvae aquatic.