Wednesday, July 18, 2018

Variable damselfly (Coenagrion pulchellum)

The Variable Damselfly is an uncommon species which occurs in widely scattered colonies throughout Britain but it can be abundant where it occurs. This picture was taken at Baston Fen in South Lincolnshire - a well known and good site for the species - on 3 July 2018.

Variable Damselfly male (Canon 80D, 100mm macro, F11, 1/250s, ISO 400)
I have seen the species at a few other sites in the region around Peterborough, but most consist and abundant at Baston Fen. In general, I would say it looks a bit daintier and darker than the very common Azure Damselfly (C. puella) with which it tends to occur. Males are fairly easily separated: the mark on the 2nd abdominal segment is typically shaped like a wineglass in C. pulchellum (but like a tumbler in C. puella - i.e. "U" shaped and not connected to the basal black band of the segment); the antihumeral stripes (the pale stripes running longitudinal down the thorax) are interrupted in C. pulchellum (broader and continuous in C. puella) and the 9th abdominal segment is mostly black with only a narrow, basal blue stripe (9th segment half or more blue in C. puella). However these features are quite variable (hence the name - Variable Damselfly!) especially the shape of the mark on the 2nd abdominal segment of the male.