For the hemerobiids that have a rounded forewing apex, the next feature to look at is whether there is a recurrent humeral vein present. The recurrant humeral vein is the first/basal vein in the costal area that curves strongly backwards with numerous branches coming off it (see below image).
If the recurrent humeral vein is present click here, if it is absent – the first/basal branch in the costal area is either simple or maybe forked once, but not curving backwards – see below.
The species with a simple humeral vein are Psectra diptera and the three species of Micromus, M. variegatus, M. angulatus, M. paganus.
Psectra diptera
This species can be identified by having two branches of R, and sometimes with very reduced hind wings (see image below).
Micromus
There are three species of Micromus present in the British Isles. One species, Micromus variegatus, is easy to identify without a microscope.
Micromus variegatus
M. variegatus is a small Lacewing with a brown body and distinctive colour pattern on the forewings – pale wings with three large brown spots, one on the apex and two on either side (see image below).
The other two species (M. angulatus, M. paganus) are a bit more difficult to differentiate without a microscope. The main features for identification are shown in the below images. The wing venation may help, especially with regards to the number of R branches. This however is not always accurate as M. paganus can also have four branches.
The most accurate way to identify the species is to look at the male genitalia (see below image).
