Ruddy Darter - Sympetrum sanguineum

Adult size

Overall length: 34 - 39mm   Hindwing length: 24 - 29m

Distinguishing features

Less common than the similar Common Darter it can be distinguished by the blood-red colour in mature males and markedly waisted appearance. Has all black legs. Care must be taken with identification with females but can be done by looking for the right features. Can be found in similar habitats to Common Dater & has a similar late summer-autumn flight period.

Identification - for help with terms see glossary

Mature males

The males’ abdomen is a striking blood-red with maturity, the thorax is red-brown and the eyes are a deep ruby red. The sides of the thorax are dark with no yellow. The legs are all back. There is a very noticeable constriction of the abdomen around segment four and towards the tail the abdomen broadens giving a club-shaped appearance.

Immature males

Immature start as with Common Darter with same basic colouration as the females and have a yellow abdomen, pale brown thorax and eyes. Waisted appearance separates it from female. As they age the abdominal blood–red colour will gradually develop.

Mature females

Females have an all yellow abdomen, brown eyes and yellow thorax which have no antehumeral stripes, but a small black ‘T’ shaped marking on the top of the thorax. Legs are all black. As with Common Daters females can begin to take on male like orange-red colouration along the edges of segments and down centre of abdomen and can also darken with age to an olive-brown colour.

Immature females

Not different from mature female perhaps slightly paler.

Habitat

Can be found at many still water sites; ponds, lakes, canals, ditches and sometimes sluggish rivers and streams. Often associated with very well vegetated habitats and in woodland sites.

Behaviour

Males will be territorial as with other darters and will often find a perch such as a twig or log but often not close to the water’s edge. They are territorial and will chaser off intruders and other males. Females more likely to be found away from water. Like Common Darters, males and females can be seen in tandem while egg laying where the male will swing the female downwards dipping her abdomen in the water, but females will also do this alone.
 

Status and distribution

More common in eastern and southern England & Ireland, but increasingly its range north and westwards. Seems patchily distributed across Dorset but could be under recorded.



Flight period

Main flight period is June to October peaking in July & August.

Similar species

Males may be confused with the Common Darter, however the latter is noticeably larger, and does not have a waisted appearance.  Ruddy Darter legs are black not striped. The colour of a mature male Ruddy Darter is a much deeper blood-red than the Common Darter. Female Ruddy darters have no antehumeral stripes but do have a ‘T’ shaped marking on the top of the thorax. Female Black Darters have yellow and black stripes on the thorax when seen from the side with small yellow dots, unique to this species.

More photographs

Click on the photos below to enlarge...

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