Originally published 10/07/2015.
The White-faced Darter, Leucorrhinia dubia, is the dragonfly that sparked my interest in this fascinating group of insects and so it seems only fitting to finish ‘A Dragonfly a Day’ with the insect that inspired it. Having volunteered on the White-faced Darter re-introduction in Delamere Forest, Cheshire, I am one of a lucky few that has spent many hours on two of the English White-faced Darter sites and the Delamere re-introduction site. I have been lucky enough to see this insect in its larval form, during its emergence, in its adult form and during copulation. It is a beautiful dragonfly and luckily, an relatively easy one to identify as a beginner.
The White-faced Darter is a specialist of lowland raised peatbogs. It chooses to lay its eggs into submerged sphagnum moss, within acidic bog pools.
The White-faced Darter is listed on the British Odonata Red Data List as an endangered species, partly due to a loss of this specialist habitat. The most Southerly point for this species is a population at Chartley Moss in Staffordshire but its main range is currently in Northern Scotland, where there are a few local populations. As you move down through Scotland into England populations become scarce, with only a handful of populations in England, including the two English re-introduced populations.
Both sexes have a creamy-white face (frons), dark eyes and black legs. Both sexes also have a mostly black thorax and abdomen. Their wings all have small dark patches at the bases and dark brown wing spots (pterostigma), that have white veins coming away from them- though these are very difficult to see.
Males: the abdomen has red markings on the top of segments 1-7 with the last segments being mostly black. The thorax has red shoulder stripes and two red stripes on each side.
Females: the abdomen has yellow markings on the top of segments 1-7, more extensive than in the males. This yellow colouration can darken with age and may even turn reddish. The thorax has yellow shoulder stripes and two yellow stripes on each side.
Male and female White-faced Darters will show slightly different behaviours. Both sexes will spend their first few days after emergence- their teneral stage- feeding in scrub or light woodland. Here they will feed until sexually mature. Males will then move back to the breeding pools, where they will hold territory over small patches of water. Although less aggressive than other Darters, they will often be seen chasing intruders away. As their name suggests, they will often dart around, returning more often than not to a selected perch within their territory. Females appear less interested in mating straight away and tend to stay longer within a scrubby or light woodland habitat. They will head to the breeding pools a little later than males.
The Black Darter, Sympetrum danae, can sometimes be confused with the White-faced Darter. The male Black Darter is unmistakable as it has a mostly black abdomen, with some small yellow markings down the sides. This looks completely different to the red and black male White-faced Darter. Immature and female Black Darters however are very similar to the female White-faced Darter, all being black with yellow markings. The best feature to use to distinguish between these individuals is the face, this will be yellow in the Black Darter and creamy-white in the White-faced Darter. The White-faced Darter also has dark patches at the base of each wing, whereas the Black Darter has either clear wings or yellow patches at the base of each wing. Lastly, if in doubt, take a photo and ask for help with the identification.
2,347 total views, 2 views today