Parasemidalis fuscipennis

Although thin on the ground, this species occurs in much of eastern England, the Midlands and Wales, so was considered a likely addition to the Norfolk list before the first was found in 2023.

This species differs from all other fresh clean waxflies in being entirely grey, not white. However, this is not sufficient alone to identify a fuscipennis, especially at a new location where it is not already known to occur. The white powder on other waxflies often becomes grey in time, perhaps due to wear or dampness, and it is very common to see waxflies with partly-grey wings. Entirely grey examples are less commonly encountered, so any fully-grey waxfly is certainly worth checking carefully.

Parasemidalis hindwings are a little smaller than the forewings (unlike Conwentzia and some Helicoconis where they are much smaller). The median vein in the forewing forks before the cross-vein RMCV above it (of which there is only one) but, unlike in Semidalis, after the cross-vein MCCV below it. Vein M in the hindwing is forked, as in Semidalis but unlike Coniopteryx. The male genitalia are very distinctive.

I caught this individual in East Sussex. The insect was far from fresh so I didn't think anything of the grey coloration, otherwise I might have taken more photos of the live waxfly. The wing-venation pointed to fuscipennis and the genitalia confirmed this. Note that it was just about possible to make out a shadow of the main genitalic features without first clearing the abdomen, though this was far easier to see once cleared in potassium hydroxide solution.

male Parasemidalis fuscipennis showing close-up of antennae, all four wings, annotated forewing marking the key veinal characters, forewing and hindwing to scale and tip of abdomen from side (uncleared and cleared), High Hurstwood (East Sussex, UK), 23rd July 2022

This one turned up in my garden and was the first county record. I noted it had fully-grey wings, but it was a worn insect so I did not get too excited about this. However the genitalia and the wing pattern both confirmed that it was indeed Norfolk's first Parasemidalis fuscipennis.

male Parasemidalis fuscipennis showing antennae, wings (including close-ups of each wing) and abdomen fro side (2 views), North Elmham (Norfolk, UK), 28th July 2023