Sunday, 27 March 2016

Emerging Polycanthagyna erythromelas at Ba Vi

Today, March 27, I went to Ba Vi in search for birds, because it was cloudy and cold (14 degrees at Ba Vi). And pretty early in the season anyway. Near the French Camp there is a smallish pond and checking the overhanging vegetation I noticed an Aeshnid hanging from a stick, apparently freshly emerged. The reddish abdomen pointed to Polycanthagyna erythromelas and indeed, that was what it was. The teneral male looks more like the female and not at all like the mature male in coloration. Even the pattern of the adult male on the abdomen is not visible. Also interesting: the postfrons of the mature insect is all black, but here it is clear that the underlying pattern is that of a T-spot. This individual was holding on to its exuviae, which was very clearly that of an Aeshnid. I had already observed a female once on April 4, but this is the first time I have seen it in March.

A cloudy and dark day I had to go to iso 1600, so it is rather grainy.

With flash that problem was solved, but I only had my macro lens with me and internal camera flash, so the result leaves a lot to be desired. Note the black T-spot on the postfrons.