Scrace Blue Tailed Damselfly (Ischnura pumilio)

Size: - Approximate Length 30mm - Wing Span 34mm.

Male: - Similar in appearance to its close relative I. elegans, with the upper surface of the abdomen being entirely black, apart from a blue band spanning segment 9 and extending slightly into the posterior of segment 8. This differs from I. elegans where the blue band is restricted to abdominal segment 8. I. pumilio has a small black mark, one on either flank of the upper surface of segment 9. The extent of this black mark is somewhat variable.

This narrative was kindly written and supplied by Mr Ken Crick

All Photography by Chris Brooks

Click on the thumb-nails to enlarge the images.

Female: - In its sexually immature form, it can be most striking, with bright orange flanks to the thorax, eyes abdomen and legs. The upper surface of segment 2 is also orange. The upper surface of the thorax displays a black tapered stripe from the pronotum ( plate just behind the head ) to the wings. Mature females are best viewed in the presence of males. Their abdomens upper surface, particularly towards the rear lacks lustre and is charcoal black. The thorax is a pale green and may exhibit some hint of orange. The antehumeral stripes are broad and are defined by a fine black line, being the same colour as the abdominal flanks.

Status: - This species is considered, by some, to be potentially under threat. It can be found in East and West Eire and below a line drawn from Anglesey to the Thames Estuary. Its localized populations can be restricted by habitat constraints, though it has colonized a number of mineral and gravel extraction site seepages in recent decades.

Habitat: - Mineral rich warm and exposed seepages, runnels, shallow flushes and pools which are subject to disturbance by large herbivores or machinery.

These water bodies are characterised by a lack of aquatic and terrestrial vegetation.

Flight period: - June, July and early August.

General: - Diminutive Blue Tail Damselflies (Ischnura elegans) can easily match Ischnura pumilio for size, increasing the risk of confusion. The specific habitat

requirements restrict the locations where this species can be found. Local to a suitable site they can be abundant. They will be located flying low down amongst the limited amount of short vegetation in and

adjacent to the chosen water body. Over aggressive disturbance can result in a strong vertical flight after which denser more prominent cover is sought. Females are often pursued and detained on the ground; there ensues a short struggle, after which the female generally agrees to copulate. Copulation can last well in excess of one hour. Females egg lay alone and not in tandem. The male may choose to stand guard while egg laying is in progress.