Scarce Blue-tailed Damselfly

Name

Ischnura pumilio (Charpentier, 1825)

Family:

Coenagrionidae

Status in Britain and Ireland:

scarce and local

Near Threatened (GB Red List) Vulnerable (Irish Red List)

Local Status:

rare

Size:

Overall body length 26-31mm
Hindwing length 14-18mm

Flight period:

Late May until July

Scarce Blue-tailed Damselfly male
Photograph © B. Kemp

Male Scarce Blue-tailed Damselfly

The body is black apart from the rear of segment 8 and the whole of segment 9 which are blue. Segment 9 also has 2 small black spots. The thorax is blue with a black dorsal face enclosing narrow blue antehumeral stripes. The eyes are blue or blue-green and the legs are black. The wings are clear with a distinctive diamond shaped bicoloured pterostigma (two toned black and white wing spot).

Scarce Blue-tailed Damselfly female
Photograph © J. Kernohan

Female Scarce Blue-tailed Damselfly

The immature female (form aurantiaca) has a diagnostic orange body and thorax. The dorsal surface is black from segments 4-8. On maturity the colour changes to green- brown and the upper side of the abdomen is completely black.

Similar Species

The male Red-eyed Damselfly is similar due to blue colouration at the end of the abdomen but is far more robust with red eyes. Blue-tailed Damselfly is very similar and is common and widespread in Shropshire. The blue area is higher up the abdomen in Blue-tailed Damselfly, occupying only segment 8 and not segment 9. Blue-tailed Damselfly is larger and has longer pterostigma. Males and females also have a distinctive lobe on the hind edge of the pronotum, absent in Scarce Blue-tailed Damselflies. Female Blue-tailed Damselflies are not orange when immature. This species is rare in Shropshire and restricted to specific habitat unlike the common and widespread Blue-tailed Damselfly.

Behaviour

Rather a weak flier that tends to rest amongst vegetation. Pairs in tandem can often be found amongst the vegetation before flying to the ovipostion site. Here they part and the male usually guards the female while she oviposits alone into emergent vegetation.

Habitat

Prefers the shallow water of spring fed seepages with a slow rate of flow and with very little vegetation. Can also be found in ditches and at man-made sites where wheel ruts have created shallow pools and at the boggy edges of pools.

Shropshire Distribution

The last county publication (Lockton et al.1996) referred to just 2 historic records- 1 at Whixall Moss (1969) and 1 in Gulley Green (1990). Since publication there have been 2 ‘one-off’ records in Granville Country Park (2005) and Llanymynech Hill (2006). More significantly Scarce Blue-tailed Damselfly was recorded at Titterstone Clee in 2006 and then again in 2011, 2012, 2014 and 2015. In addition a number of exuviae were found at this location in 2006 confirming successful breeding. This species was also recorded in the privately owned Bromfield quarry (2011).

Shropshire Distribution Map (SEDN)

Scarce Blue-tailed Damselfly Shropshire distribution
© Crown copyright 2016 OS 100049049

Where to see in Shropshire

Scarce Blue-tailed Damselfly inhabits water bodies typically in early successional stages meaning their presence at a particular location is often transient, but this does mean they could unexpectedly be recorded at new suitable habitats. Titterstone Clee Hill is currently the most likely site in which to find this species.

 

National Distribution