Common flatwing (Austroargiolestes icteromelas)
Mature males are readily identifiable by the thorax (only) being very pruinose.
Mature females can also be quite pruinescent on the thorax.
These are medium-sized damselflies that perch with their wings spread flat (except shortly after emerging). This one is a young female and the pterostigma colour should darken on maturity.
The common flatwing is a very common species of damselfly of the subfamily Argiolestinae in the family Megapodagrionidae. It is also as the Australian flatwing.