Raphidioptera (Snakeflies) Identification

There are four species of Raphidioptera in the British Isles: Phaeostigma notata, Atlantoraphidia maculicollis, Xanthostigma xanthostigma, and Subilla confinis. Adults of Phaeostigma notata and Atlantoraphidia maculicollis can be identified in the field and from good quality photographs. Xanthostigma xanthostigma and Subilla confinis require the hind wing venation to be observed to identify confidently, however there are features from the body and forewing that can be used to potentially identify these species.

Phaeostigma notata

Phaeostigma notata identification features. Images: wing Rintala & Lehto (CC BY 4.0) and main image Nielsen (CC BY 4.0)

Atlantoraphidia maculicollis

Atlantoraphidia maculicollis identification features. Image Pudding4brains (Public domain)

Xanthostigma xanthostigma and Subilla confinis

These species both have the pterostigma as long as the cell below (cell 1), they are easily separated by the basal branch of MA in the hindwing. This feature however is difficult to see from photographs, however it can be observed in the field with a hand lens and gentle manipulation of the insect.

The basal branch of MA is the easiest way to differentiate between these two species

Some body and forewing features may also help to identify these species. The body features are the colour of the scape (first segment of the antennae) and the sculpture of the head (smooth or coarse). The forewing features are the number of veins coming of cell 1 and 2.

Body and forewing features of Xanthostigma xanthostigma and Subilla confinis. Images: Nielsen (CC BY 4.0) and Mondy (CC BY NC)

Raphidia ophiopsis

This species is present in Fenno-Scandinavia and could potentially be found in Scotland. It is very similar to Phaeostigma notata, but differing in having only one crossvein in the pterostigma and less than 10 crossveins in the costal area.

Identification features for Raphidia ophiopsis. Main image: Lohmann (CC BY NC ND)