21-Small Bluetail – Scarce Blue-tailed Damselfly – Ischnura pumilio- UK European Dragonfly Photo
The Small Bluetail – Scarce-Blue-tailed damselfly (Ischnura pumilio) is aptly named as being scarce in the UK unlike its congener the Common Bluetail – Common Blue-tailed Damselfly (Ischnura elegans). Population density is often low at well dispersed sites although on occasion in newly created habitat it can be abundant for a while until the vegetation changes. One such notable occurrence was in the Forest of Dean in 1983 where open-cast coal mining had ceased . At one newly created nature reserve, Woorgreens Lake, many thousands were observed but within a few years vegetation had grown up and numbers were much reduced. Low and sparse vegetation with shallow water in small ponds and seepages is favoured such as often found in quarries as shown in the habitat photo below. It is one of the smallest damselflies and can be difficult to see even in ideal lighting.
KEY I/D FEATURES :
Mature males differ from the Common Bluetail in that the blue ‘tail-light’ appears on both Segment 9 and the lower part of Segment 8. There are often two black comma shaped marks on the blue at the sides of S 9. In the hand the bi-coloured pterostigma is significantly larger on the forewing than the hindwing. Also under the lens the pronotum is smoothly arched unlike the projection on the Common Bluetail.
Mature females have an all black body with no ‘tail light’ and are even more difficult to find. When immature however they stand out with their beautiful extensive pink on the head, thorax and abdomen. Not to be missed !