Aeshna isoceles (Green-eyed Hawker/Norfolk Hawker)
This species is termed the Norfolk Hawker in Britain because its range was originally restricted to Norfolk. However, it’s breeding range has now spread and includes Suffolk, Kent and Cambridgeshire at least so Green-eyed Hawker, the name suggested by Dijkstra/Lewington, which has always been more appropriate in a European context , also seems more appropriate in th UK, now.
Vernacular names aside, confusion also reigns when it comes to binomials. Originally in the Anaciaeshna genus, it is most recently placed in the Aeshna genus (there are apparently significant differences between it and other Aeshnidae, though it apparently doesn’t fit Anasiaeshna either). Confusion continues to the species name which is variouly written A. isosceles [R. R. Askew] and A. isoceles [Dijkstra/Lewington and JP Boudot et al]. Personal opinion: since it is named for the distinctive isosceles triangle on the top of abdominal segment 2, It should be A. isosceles and some later otherwise revered fellow couldn’t spell, so I’m with R. R. Askew.
Whatever we call it, we made a trip up to the Norfolk Broads in search of these delightful creatures and managed to find a good selection. They may be tagged as rare but they seemed locally abundant to me.
- Brown thorax and abdomen with clear wings (contrast with A. grandis)
- Distinctive/diagnostic yellow triangle on dorsal side of S2
- Green eyes (when mature)