Variegated Strider Pachyprotasis variegata

This came to light on the edge of wet woodland. Before keying it I thought I'd see if ObsIdentify could lend a hand. This app was 100% certain it was Pachyprotasis rapae, but even when ObsIdentify is 100% sure that doesn't necessarily mean it's right. A quick search for that species revealed that it did indeed look much like my specimen and that was one of the commonest sawflies (so surprising I hadn't seen one before maybe), so I imagined it was probably correct. But I noted that there were a couple of similar species that were less common, so these needed eliminating before I trusted the app. The description of rapae at the excellent sawflies.org.uk website rang alarm bells and I turned to the RES key for backup. Sure enough, the app was wrong - this wasn't the very common rapae (I still need to find that...). The white apical margins of the tergites (actualy they're not white as stated in the key and website, they're creamy-yellow) were clearly broadened in the middle and the pattern of the mesopleura was wrong too. This was therefore either variegata or the rarer similans and identified as variegata based on the frons having very clear microsculpture between the distinct punctures (shining with weak microsculpture on simulans) and the large size.

male Variegated Strider Pachyprotasis variegata showing underparts, abdominal tergites, mesopleura (2 views), hind femur, frons and forewing, Wendling Beck Environment Project (Norfolk, UK), 15th May 2024