Nysius senecionis

The clear-cut dark bases to the second segment of the antennae helped ID this, having ruled out huttoni by the shorter hairs on the clavus and general shape. At first I wasn't quite sure if I could eliminate graminicola as the length of the first segment of the hind tarsus seemed to be about the same as the second and third segments combined, not shorter as described on the British Bugs website. However due to the curvature this was difficult to measure precisely, and after checking Kirby this allows for the first segment to be "not or scarcely longer" which fits ok. The bucculae (the ridge adjacent to the rostrum - a new term for me) were close to even height, although a shade narrower towards the rear. There were vague longitudinal stripes on the thorax.

Nysius senecionis showing thorax and antennal bases, hind tarsus and bucculae, Wendling Beck Environment Project (Norfolk, UK), 29th April 2023

This one turned up in a clearwing pheremone lure trap in my garden, the first I've seen here. It was alive in the photo, but didn't seem to have the energy to stretch its legs out.

Nysius senecionis showing antenna and hind tarsus, North Elmham (Norfolk, UK), 10th May 2023

When I was researching the ID for the ones above I didn't notice the mention on the British Bugs website of the extent of matt area of the metapleuron, so I've added a photo of that here. These came to LED lights on a sheet during a one-hour survey - at least six of them. The first and second photos are possibly the same individual and the first photo is certainly the one for which I've included close-up photos further down.

4-5x Nysius senecionis showing metapleuron, clavus hairs and hind tarsus, Wendling Beck Environment Project (Norfolk, UK), 14th May 2023

These two came to light and were problematic. Kirby's draft key (2015) requires senecionis to have the first hind tarsomere to be "not or scarcely longer than" the second and third combined, or "distinctly longer than second and third together" on other species (huttoni having already been discounted). On the second of these you could just about argue that it was scarcely longer, though at about 15% longer that would be a stretch, but on the first it was 25% longer. Despite other characters seemingly resembling senecionis, I thought they couldn't possibly be. However I had problems keying them otherwise with none of the other species showing the combination of characters shown by these two. I checked the genital capsule of one (I meant to check both but unfortunately it slipped out of my tweezers and was lost on the second) and this confirmed that it was neither of the species it keyed closest to.

The key doesn't show the genital capsule for senecionis but I found this illustrated elsewhere and mine, the first one at least, matches senecionis. Of the two this was the one where the relative tarsomere lengths was worst for senecionis, so as both individuals ticked all other boxes for senecionis I'm happy that's what they both were.

male Nysius senecionis showing hind tarsus, buccula, metapleuron and genital capsule (2 views), Wendling Beck Environment Project (Norfolk, UK), 6th August 2025

second male Nysius senecionis showing hind tarsus, buccula, metapleuron and hairs on clavus and scutellum (2 views), Wendling Beck Environment Project (Norfolk, UK), 6th August 2025