Description
Length: 33-44mm
Flight period: UK records from mid-June to early September
This darter has a flattened abdomen appearing rather broad compared to other UK darters.
Male: vividly bright scarlet and unmistakeable. The veins on the leading edges of the wings are also red.
Females and immatures: yellow-brown with a conspicuous pale stripe along the top of the thorax, between the wings.