Posted by Graeme Lyons , Monday, 10 December 2012 21:06
Last week I was identifying some invertebrates from a survey I did of the lake at Woods Mill in the autumn of last year and this summer. Having identified all the beetles I was working on the dragonflies and damselflies. The first big shock was that I didn't record a single dragonfly nymph AT ALL! No doubt eaten by the carp. Working through the damselfly nymphs I recorded four species. Several Blue-tailed Damselflies, a few Azures and a single Large Red. One large species however dominated the samples being both the most numerous and the largest at nearly 30 mm. What was strange though was that this species, although known from the lake, never appears that numerous. The Red-eyed Damselfly nymph is an impressive creature with strange and beautiful 'caudal lamellae' (the three 'tails' at the tip of the abdomen). These structures which are used for respiration, are particularly well marked in this species, there is something distinctly oriental about them. I wonder if something in this species's behaviour allows it to evade the carp? It was fascinating to learn to identify a different stage in a group of species I know so well. Next time I get a minute to work through the samples, I will try the case-bearing caddisfly larvae.