Chrysis terminata

One of the spectacular jewel-like ruby-tailed wasps.

This was the first ruby-tailed wasp I attempted to key to species, though I had a female Chrysopa ignita from my garden collected in 2021 in a pot awaiting examination, and I looked at that straight after in order to make direct comparisons. I used Michael Archer's key to identify this and also referred to the 1960 RES handbook. The latter wasn't much help as it doesn't cover terminata - this species was only added to the UK list in 2016.

Viewing the frontal carina was tricky - and photographing it even harder. Holding the insect still at an angle where you could see the teeth was a challenge. But teeth there were!

Compared to the Chrysis terminata that I examined at the same time there were a number of fairly obvious differences. It was smaller, the thorax was much bluer, the abdomen was a more orangey pink and the frontal carina was much less pronounced (and less toothy). The teeth on the posterior margin of the third tergite were similar but a little longer and sharper.

female Chrysis terminata showing tergites (third tergite teeth and general), frontal carina (from front also showing scapal basin, and from above showing teeth), thorax (side view and dorsal view of rear showing propodeal and metapleural teeth), mid tibia and tarsus and sternites, Foulden Common (Norfolk, UK), 27th May 2023