Trioza galii

This was, I thought, my first Trioza urticae. It was followed pretty soon by a number of other urticae and perhaps if I'd seen those first I might have realised this one wasn't urticae. I'm grateful to James Emerson for drawing my attention to its correct identity.

The point in the RES key where I went wrong was judging the length of vein R_s - it's longer on urticae, cutting the costal vein distal to the point where vein M forks. In my defence, I'd argue that it does - though compared to real urticae it's closer to level with the fork in vein M, almost level - it's more obviously distal in urticae. In any case vein R_s is aberrant in this specimen with it arising from vein M instead of vein R, though with an extra short vein linking it with vein R. In hindsight I can see that the wing is broader than on urticae.

Trioza galii has relatively triangular genal cones - a bit shorter than on urticae (not that I noticed) but otherwise similar. James has pointed out that this was shorter and more hump-backed than urticae and has a different colour pattern. I'd noticed it was blacker than others but that hadn't rung alarm bells as urticae is a bit variable. But it also lacks the white stripe along the side that's normally present on urticae and instead has an orange and white band across the abdomen.

This individual was swept from Garlic Mustard but is normally associated with Galium - there may well have been Cleavers growing in the same area.

Trioza galii showing forewing including close-ups of spinules around Cu₂ and apical region, North Elmham Cathedral Meadows (Norfolk, UK), 28th April 2021