Sisyra nigra (formerly Sisyra fuscata)

A fairly common species of spongefly, the only one confirmed to have occurred in Norfolk. My records have all between early June and early August (mostly July) but there are records of adults in May and September.

Spongeflies may be told from similar brown lacewings (e.g. Sympherobius spp.) by looking at the costal cross-veins - in spongeflies these are mostly unforked, whereas in similar brown lacewings they are forked before reaching the edge of the wing. Also they lack the recurrent humeral vein present in many (not all but including Sympherobius) brown lacewings.

Sisyra nigra has entirely dark antennae (unlike Sisyra terminalis which has pale tips and the European Sisyra jutlandica where the bases of the antennae are slightly yellowish) and uniform wings with the membrane almost as dark as the veins (unlike Sisyra dalii which has a lighter membrane with small dark marks around the cross-veins). Ideally male genitalia will be checked by examining the tip of the abdomen from above.

In the unlikely event that one of the other species of spongefly is found in Norfolk, please retain a specimen.

male Sisyra nigra showing wings and abdomen tip, Dillington Carr (Norfolk, UK), 1st May 2022

male Sisyra nigra showing cleared abdomen tip (ventral and side views), North Elmham (Norfolk, UK), 29th July 2018

male Sisyra nigra, North Elmham (Norfolk, UK), 29th July 2018

male Sisyra nigra, North Elmham (Norfolk, UK), 23rd July 2020

male Sisyra nigra showing forewing and hindwing, North Elmham (Norfolk, UK), 11th July 2019

male Sisyra nigra showing forewing, North Elmham (Norfolk, UK), 10th June 2017

female Sisyra nigra showing tip of abdomen from side, North Elmham (Norfolk, UK), 7th August 2020

female Sisyra nigra, North Elmham (Norfolk, UK), 7th August 2020

male Sisyra nigra, North Elmham (Norfolk, UK), 18th July 2020

male Sisyra nigra, North Elmham (Norfolk, UK), 24th July 2019