Wesmaelius subnebulosus

According to Plant (1997) this is probably our commonest brown lacewing, however that doesn't seem to be the case in Norfolk where there are considerably more records of several species of Hemerobius. It is however the most often-recorded Wesmaelius in Norfolk, albeit not the one I've come across most often personally. Apart from one found indoors in December, Norfolk records span from April to September.

Like Hemerobius, Wesmaelius has a recurrent humeral vein but unlike Hemerobius the cross vein RMCV falls distal to the fork in vein M. Separating the various species of Wesmaelius from one another usually requires examination of the tip of the abdomen. This is hard to do on live specimens so it will normally be necessary to retain specimens for identification.

The shape of the appendage at the tip of the abdomen is crucial for identifying males. On females you need to look at the genital plate which is best viewed by clearing the abdomen in, for example, potassium hydroxide solution.

male Wesmaelius subnebulosus, North Elmham (Norfolk, UK), 21st June 2017