Atractotomus parvulus

The 3 British species of Atractotemus look rather similar, blackish, covered in a mixture of black hairs (hard to see) and whitish scale-hairs. The thick second segment of the antennae is one way to tell them apart from other similar species, including a couple of similar Psallus sp. (which are also slightly bigger).

The cylindrical first segments of the antennae are shared with Atractotomus magnicornis but these are more triangular in Atractotomus mali. The easiest way to tell parvulus from magnicornis is by the male's aedeagus, though there are also differences in tarsal claw shape and length of the second segment of the antennae. The strongly-curved aedeagus with long tapered apex extending well past the ring-like secondary gonopore is easy to see here.

male Atractotomus parvulus showing aedeagus, North Elmham (Norfolk, UK), 12th August 2020

This one is clear too:

male Atractotomus parvulus showing aedeagus, North Elmham (Norfolk, UK), 3rd August 2018

The following one caused me some problems! Firstly it was taken at a site containing lots of Hawthorn (one of the foodplants of Atractotomus mali) but no Scots Pine or Norway Spruce (supposedly the foodplants of Atractotomus parvulus and Atractotomus magnicornis although I'm not sure which way round as different sources contradict on this). Well the first segment of the antenna was clearly cylindrical so that ruled out mali, so next step was to examine the aedeagus.

This was strongly-curved s-shaped which fits parvulus and isn't as illustrated for magnicornis but I couldn't see the tapered tip extending past the secondary gonopore. At one end of the aedeagus was what I initially took to be the abruptly cusped apex of magnicornis. There was something that looked vaguely ring-like which I thought must be the secondary gonopore and beyond this just a short point, pretty much like shown for magnicornis. But given the overall shape of the aedeagus and the fact that I couldn't completely convince myself that I was really looking at the secondary gonopore, I looked for other clues.

Magnicornis is supposed to have a longer second segment of the antenna. The diagrams of the antennae for the two species show it as being 4.5 times longer than the first segment on magnicornis and about 3 times longer on parvulus. On mine it as about 3.8 times longer, so smack bang in the middle! There's also a difference in the tarsal claw shape. This isn't easy to see as the claws are pretty small, but I eventually managed to see it at the right angle under high enough magnification, and this clearly pointed to parvulus.

By now I was pretty confused, so I looked at my photos of my previous records of Atractotomus (all of which were parvulus). One look at the aedeagus and I realised where I was going wrong - I was looking at the wrong end of it! The secondary gonopore was missing. I'm not quite sure if it is just that missing from the side or if the whole tip is broken off, but in any case, based on the overall shape of the aedeagus and the tarsal claw, I'm now happy calling it parvulus.

male Atractotomus parvulus showing first two segments of an antenna, aedeagus (4 orientations), tarsal claw and left clasper, North Elmham Cathedral Meadows (Norfolk, UK), 14th August 2021

male Atractotomus parvulus, North Elmham (Norfolk, UK), 11th August 2020