Yellow-tailed Yam Tipula pierrei

This cranefly came to light in a meadow that's recently been taken out of arable cultivation. Small numbers of cattle have spent periods of time grazing in the meadow since it was taken out of agriculture. It was caught along with a Tipula lateralis which made for a nice comparison and some of the photos below show the wings, abdomens and genitalia of both together for comparison (always the pierrei above and lateralis below).

The wings had a similar pattern but the pattern was less distinct on the pierrei and this was also noticeably browner. The pierrei was significantly smaller (wing length about 14mm vs. 17mm for the lateralis). Both were females but the abdomen was distincly broader on the lateralis, and the pale central stripe down the abdomen was deeper more orangey-yellow on the pierrei. At first glance the antennae looked dark which made me doubt that it was pierrei (Stubbs says the antennae are mainly yellowish), however on closer inspection it became clear that the basal segmments were yellow, and most of the rest of the segments were slightly yellow - on the lateralis it was completely grey. Boardman describes pierrei as having the basal two segments yellow and the rest darker, though retaining some yellow colouration - this description matches mine more comfortably that Stubbs' "extensively yellow". The rostrum was distinctly yellow contrasting with the grey head, though this was also true on the lateralis (supposed to be grey) - but it was more obviously yellow on the pierrei.

The feature that initially put me on to the possibility that it was pierrei (as I keyed it using Stubbs) was the shape of the keel at the bottom of segment 8. This broadened abruptly towards the base unlike on the lateralis which was gently curved. (see red arrows in comparative photo below). There was also a difference in the lateral 'wings' of the cerci when looking from above or below - these were much broader, or at least splayed outwards more, on the lateralis. This isn't mentioned in the keys so I don't know if it's a constant difference between the two species or not.

female Yellow-tailed Yam Tipula pierrei showing wing, abdomen tip from side, rostrum, antennae (2 focuses), Wendling Beck Environment Project (Norfolk, UK), 26th Aguust 2024

comparisons between same female Yellow-tailed Yam Tipula pierrei (always above) and a female Common Yam Tipula lateralis (always below) showing wings, abdomens (from above), tips of abdomens (from side, top and bottom), Wendling Beck Environment Project (Norfolk, UK), 26th Aguust 2024