Sedge Sprite (NPS National Capital Region Odonata)

Sedge Sprite

Nehalennia irene

Summary ⁶

Nehalennia irene is a species of damselfly in the family Coenagrionidae. This species is commonly known as the sedge sprite.

General description ⁷

Sedge sprites are among the smallest of all damselfly species with slender abdomens and a total length less than 3 cm (Westfall and May 1996). Generally, they are metallic green with no post-ocular spots (pale-coloured markings just behind eyes, characteristic of many damselflies) (Walker 1953). Male sedge sprites are fairly easy to recognize due to the blue colour of the terminal two and a half abdominal segments with paired dark spots on the terminal two segments (Walker 1953). Females are very similar to males but the two terminal abdominal segments are each dark with a blue band (Westfall and May 1996). Females exhibit two colour and pattern morphs, one similar to the male and one with green and yellow colouration (Lajeunesse and Forbes 2003). The sedge sprite is of similar size and colouration to some species from the forktail genus (Ischnura) but differ in that forktails have obvious postocular spots (Acorn 2004). Larvae, like the adults, are small and slender. They are green or brown and have no obvious markings (Walker 1953). Identifying characters include spots on and below the margins of the gills and a dozen small spines on each side of the head towards the back (Westfall and May 1996). They are found at the base of dense, aquatic vegetation in habitats where adults fly (Westfall and May 1996). At the genus level, sprite larvae have one prominent (sometimes a second, but never none) bristle on either side of the upper lip just above the mandibles; although this character separates them from forktails it is not particular to sprites (De Marmels 1984).