Azure Damselfly - Coenagrion puella
Adult sizeOverall length: 33 - 35mm Hindwing length: 16 -23mm
Distinguishing featuresOne of the two most common of the five species of ‘blue’ damselflies found in Dorset, the other being the Common Blue Damselfly. Look for characteristic bold U shape on segment 2 on the abdomen of males.
Identification - for help with terms see glossary
Have a characteristic black U shape on segment 2 of abdomen. Has thin but complete antehumeral stripes on thorax. Viewed from the side it has 2 stripes on side of thorax (this separates it from Common Blue Damselfly which has only one stripe). Also on segment 10 there is a bow-tie shaped black mark though this can vary.
Immature’s are a pinky brown base colour which gradually turns blue on maturity. The eyes are brown at this stage also turning blue on maturity.
Mature females occur in two forms, the more common green form which accounts for about 90% of the population has a green abdominal base colour separated by thick black markings and on segment 2 a thistle like shape. The blue from has a blue base colour with thick black markings and similar thistle shape on segment 2.
Immature's of each the colour form type can be a variety of pale brown/pink base colours with brown eyes which mature into mature colour forms
HabitatPreferred breeding habitats are well vegetated standing waters such as ponds, ditches and canals. Seems to prefer well sheltered sites. Often found with Common Blue Damselfly.
BehaviourDue to very synchronised emergence, adults can be often seen in large numbers in middle of summer at suitable sites. Males are not territorial but will be seen hovering around the margins of ponds searching for females.
Status and distributionHas a wide distribution found as far north as southern Scotland. One of commonest damselflies and found at virtually all suitable sites. Common throughout Dorset.
Flight periodMain flight period is late April to Late August, peaking in June & July.
Similar speciesVery similar to three other members of Coenagrion family which occur in Dorset. However both Southern Damselfly and Variable Damselfly are very rare and unlikely to be encountered. Main confusion will be with Common Blue Damselfly; this has a ‘club’ shape on segment 2 and single stripe on thorax. Special care must be taken with trying to identify females of this group; they are notoriously difficult, though not impossible to separate in the field!
More photographsClick on the photos below to enlarge...
All photographs by kind permission & © of Ken Dolbear unless otherwise stated. All rights reserved.