August 2014 update.
The blasted taxonomists have been at it again – studying DNA, that is – and decided that this should now be in the Thecagaster genus, thus Sombre Goldenring (Thecagaster bidentata), which is now how iNaturalist refers to it. So, until the next change, that’s what I’m calling it but, honestly, this is enough to make one prefer common names to scientific names.
All Goldenrings are, IMHO, strikingly handsome creatures, so how any one can come up with a name including the word “sombre” for this spectacular character is entirely beyond me. As a group, they are also pretty unmistakable. The individual species, however, can readily be confused. Indeed, I was guilty of spending a year thinking the individual in these pictures was a Common Goldenring (Cordulegaster boltonii), because that’s what I’d seen in this location on a previous year. I finally woke up and was delighted to find that I had another species for our catalogue.
The notes below contrast this with the more widespread Common Goldenring.
Id Notes
- Apical spots on S2&3/4 and not on S5-8
- In side view, yellow abdominal markings appear decidedly triangular
- Black occipital triangle (behind where the eyes meet – yellow in C. boltonii)
- Normally, 3 cells in the hind-wing anal triangle (5 cells in C. boltonii)
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