Dragonflies (Odonata) start their life as aquatic larvae or nymphs, passing through a series of developmental stages or ‘stadia’, undergoing several moults as they grow. Before the final moult (5), metamorphosis occurs in which the larvae transform into the adult form (6). Shining macromia dragonflies emerge in May to June, following a larval period of two to three years (2) (3) (5). After emergence, adults undergo a pre-reproductive phase known as the maturation period, and this is when individuals normally develop their full adult colour (6). The maturation period for this species is thought to last one to two weeks, and the entire adult flight period probably only lasts until the end of July to mid-August (2) (3). After maturation, males establish a 50 to 150 m territory along a stretch of river, which they regularly patrol to guard from other males. Females have been observed laying eggs in the water as soon as they arrive at the river. However, since mating at these sites seems to be rare, it is thought that copulation may be performed mainly at feeding sites elsewhere (5).
The larvae of this species probably feed on small aquatic animals, and the adults on flying insects, which they capture and devour in flight (3).