Diphlebia lestoides - Whitewater Rockmaster

Male identification: Electric blue, very large damselfly. Abdomen predominantly blue dorsally, with thin black centre line on first four segments only. Ring shaped superior anal appendages blue. Blue on thorax restricted to two large panels on dorsal surface separated by strong black centre line. Lateral thorax has olive above white. Head black with various blue markings on clypeus, frons and between eyes. Wings with noticeable white band at position two/thirds along length from base.

Female identification: Blue confined to top of abdomen with prominent black centreline. Sides of abdomen orange. Segment 8,9 and10 dark brown. Thorax and head patterned as male but blue areas replaced with dull olive. No white band in wings.

Similar species: D.nymphoides has entire thorax blue with black suture lines while face is entirely black without markings. Also has blue abdomen distinctly marked by broad black markings along centre line and at segmental junctions. Superior anal appendages black.

Behaviour: More closely resembles a dragonfly due to large size, strong direct flight and wings open at rest. 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 but occasionally at higher altitudes up to about 1400m.

Australian State distribution (from CSIRO Entomology)

Habitat: Rapids and riffles of montain rivers and streams with emergent rocks. Larvae cling to underside of large cobbles and boulders.

Status: Locally common.

Flight period: November to January