Blue-tailed Damselfly - Ischnura elegans

Adult size

Overall length: 30 - 34mm   Hindwing length: 14 - 20mm

Distinguishing features

The commonest of the four species of damselflies which have an almost solid black abdomen and a blue ‘tail’ in males, though this can be brown in females. They are very commonly distributed across UK and occurs in a wide variety of habitats  

Identification - for help with terms see glossary

Mature males

Very delicate looking damselflies they have a characteristic blue spot at the "tail" (Segment 8), blue ante-humeral stripes on the thorax and blue eyes.

Immature males

Have green ante-humeral stripes on thorax with blue tail spot.

Females (immature & mature)

Females look superficially like males but have a spine underneath segment 9. Females vary with at least 5 different colour forms! There are two immature forms: violacea has a violet thorax and rufescens has a salmon pink thorax, both have blue ‘tails’ . When mature the female has 3 colour forms: the form typica is blue like the male. The form infuscans has an olive green thorax and brown tail spot and the form infuscans-obseleta the thorax in pale brown with a blue tail. Easy!

Habitat

Will occur in a very wide range of habitats and can tolerate polluted and brackish waters. It is less tolerant of fast flowing water or very acidic conditions. Tends to be early colonisers of new sites. So can be present at almost any site but often in small numbers.
 

Behaviour

Both males and females can be found on emergent and bankside vegetation. Males can be territorial. They will be often seen flying and active in dull and cool conditions unlike other damselflies. 

Status and distribution

Has a very wide distribution found throughout Britain including Hebrides. One of commonest damselflies and found at virtually all suitable sites. Very common throughout Dorset.



Flight period

Main flight period is late April to Mid September, peaking in June, July & August.

Similar species

The related but rare Scarce Blue-tailed Damselfly superficially resembles this species but this has blue markings on segments 8 and 9. At a glance could be confused with Red-eyed Damselfly or Small Red-eyed Damselfly but they are delicate, less robust looking insects and do not have red eyes.

More photographs

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Mature Male

Mature Female - typica form

Mature Female - infuscans form

Mature Female - rufescens -obsoleta form

Mating Pair (female infuscans form) 

All photographs by kind permission & © of Ken Dolbear unless otherwise stated. All rights reserved.