One of two “species” that Djikstra/Lewington refers to as the Atlantic Darters, the other one being S. striolatum f. nigrescens (Highland Darter). In like vein, whether this character is an actual species in its own right or just a variation of S. striolatum (Common Darter) seems still to be open for discussion – maybe an in depth DNA study is yet to be performed. For now, I’m showing it on it’s own page as S. striolatum form nigrifemur.
These are endemic to the Canary Islands and Madeira, the latter being where we spotted our specimen. They exhibit minor differences to S. striolatum, the most visible of which (to the casual observer) is darker femurs showing less of a yellow stripe. To my eye, this resembles S. striolatum more closely than does S. striolatum f. nigresens.
Our single specimen is a red-colouration female so perhaps classed as an andromorph, just to make things more difficult. Interestingly, it shows some strong red on the side panels of the thorax, which looks unusual compared to S. striolatum, to me, anyway.
- lower legs black with yellow streaks but femurs mostly black
- ♂ – contrasting brown and light yellowish panels on side of thorax
- mature ♂ – abdomen more orange in appearance than the very red S. sanguineum
- ♀ – yellow abdomen, darkens to dull olive/greenish with age (normally)