Nysius graminicola

I had previously recorded Nysius huttoni and Nysius senecionis in the field where this came to light (ex-arable to be restored to heathland). It clearly wasn't huttoni and given its general appearance and dark base to the second segment of antennae I was fully expecting this to be another senecionis. However, the proportions of the hind tarsal segments were wrong for this species and the matt part of the metapleuron was less extensive. Moreover the bucculae clearly tapered towards the rear. The shape of the bucculae seemed to favour cyanoides or graminicola rather than ericae and thymi, but Kirby warns that this can be hard to assess, so I explored all four options. The genital aperture clearly had a pair of inward-pointing teeth on the upper section, and these differed in form to the diagram for ericae which also has teeth, but with their lower edges forming an outwardly-pointing projection too. The parameres are only shown in Kirby for ericae and thymi but are shown by Putshkov's "Fauna of Ukraine" (I haven't see the original reference but the plates for the apertures and parameres are shown here). The parameres on my individual are more curved than either of the illustrations here for graminicola but I'm not too worried about that as the same link cites Schmitz & Péricart in saying that the shape of the parameres isn't so useful. Their paper (in French) includes another set of drawings of the apertures and all in three sets of diagrams of apertures, graminicola is the one that matches mine most closely. Photos of graminicola show that this species shares the dark ring at the base of antennal segment 2 with senecionis, so that fits too. Nysius graminicola isn't currently covered in the British Bugs website but the limited information I've been able to find about its status suggests that it used to be rare but has much increased and expanded its range.

male Nysius graminicola showing antennal sements 2, bucculae (both sides), metapleuron, clavus, hind tarsus and genital opening/parameres (two views), Wendling Beck Environment Project (Norfolk, UK), 16th June 2025

This one was caught as a nymph in a pitfall trap in the same location as the one above. I probably wouldn't have been able to identify it had it stayed that way but it had moulted into an adult by the time I came to examine it.

male Nysius graminicola as nymph in first two photos then as adult showing hind tarsus, metapleuron, bucculae and genital capsule, Wendling Beck Environment Project (Norfolk, UK), 30th-31st July 2025

This was found by suction, again at the same location. I found it a little hard to see the teeth in the genital aperture clearly so isolated that side of the capsule for a clearer look.

male Nysius graminicola showing hind tarsus, metapleuron, bucculae, genital capsule and its aperture, Wendling Beck Environment Project (Norfolk, UK), 26th September 2025