Diphlebia nymphoides - Arrowhead Rockmaster

Male identification: Strikingly blue, large damselfly. Abdomen electric blue with broad black rings at segmental junctions and variously shaped broad black centreline for last two/thirds of length. Ring shaped superior anal appendages black. Thorax entirely blue with black lines along all sutures and carina. Face entirely black with no blue markings. No white bands on wings.

Female identification: Patterned similar to male but with all blue areas replaced by dull olive

Similar species: D.lestoides has predominantly blue abdomen with blue superior anal appendages and blue markings on face. Also thorax has blue confined to the dorsal surface with olive and white on sides, and white band on wings.

Behaviour: Patrols up and down section of river close to water surface perching on emergent boulders in fast flowing water.

Distribution: Mainly eastern Victoria in alpine foothills below about 600m. As yet only recorded south of the alps.

Australian State distribution (from CSIRO Entomology)

Habitat: Rapids and riffles of montain rivers and streams with emergent rocks.

Status: Locally common.

Flight period: January to February