The western demoiselle or yellow-tailed demoiselle is a species of damselfly belonging to the family Calopterygidae. It replaces the banded demoiselle in southern France and the Iberian Peninsula, and is sometimes considered a subspecies of that species .
The male of ''C.xanthostoma'' generally has more extensive colouring in the wings than that of ''C.splendens'', usually reaching to the wingtips. Unlike ''C. splendens'', the males have clear wings when first emerging as adults, only.. more