BruceH's picture

Common Darter

Observed: 8th June 2013 By: BruceHBruceH’s reputation in InvertebratesBruceH’s reputation in InvertebratesBruceH’s reputation in InvertebratesBruceH’s reputation in Invertebrates
Common Darter
Common Darter

Quite common in grassland near disused gravel pit.

Species interactions

No interactions present.


RoyW's picture

Darter IDs

The left hand image (an immature male) looks like a Ruddy Darter, S. sanguineum, because of the pinched abdomen, black extending down the sides of the frons (face), and apparently all black legs.

The right hand image (a female) could be a Common Darter, but I wouldn't rule out Southern Darter, S. meridionales, or Vagrant Darter, S. vulgatum, based on the details that can be seen in the photo.

BruceH's picture

The female

I completely agree about the left hand image - I ought to have spotted the details.

The right hand image I identified as S. striolatum on the basis that

1) it is out of range for S. vulgatum, albeit only just, and "uncommon" for S. meridionale - Dijkstra, and

2) the pterostigma for S. meridionale are clearly red coloured in Dijkstra

Am I reading too much into these details?

Also I ought not to have submitted observations of two different insects as being the same.

RoyW's picture

Right hand image.

You may well be correct that the female is S. striolatum, but I don't think that a species level identification is possible from this single photo. For female 'Sympetrums' a side view is usually of more use for identification, especially if the vulvar scale and the sides of the frons can both be seen!

Pterostigma colour is usually of very limited use I'm afraid, it will be the pale whitish colour seen here in all similar immature darters, changing to reddish, brown, or black in most (Red-veined Darter, S. fonscolombii, is one exception). It may be true that S. meridionale is more likely to have pale or red pterostigmas when mature, but that's about it.

Range is usually a good indication of which species are most likely to be found, but insect species that are described as "uncommon" in a given region can be numerous at the sites at which they do occur - and dragonflies are very capable of travelling long distances and turning up well outside the expected range (+ in some cases isolated populations may just have been overlooked in the past).

BruceH's picture

Very helpful

Thanks so much, Roy, for this really helpful response. The "season" in France has really only just started - in time for me to have returned to UK! I shall be back there in about a month however, and practising to improve my ID skills.