As with other dragonfly species, the dark whiteface has a complex life-cycle which includes a fully aquatic larval stage (2). As larvae or ‘nymphs’, dragonflies are effective sit-and-wait predators with the fascinating feature of being able to fire out the lower portion of the mouth, known as the ‘mask’, in order to grasp passing prey (2) (5) As well as being able to walk, dragonfly larvae are able to move through the water by jet propulsion, expelling water from a specialised rectal chamber in order to propel themselves along (5).
The total length of time spent in the larval stage varies between species, with some species spending a few months and others several years as a larva (2). The larva undergoes several moults before finally emerging from the water as the readily recognisable adult dragonfly (2) (6).
The adult dark whiteface is a skilled aerial predator and is usually active between May and June (2). Dragonflies are generally opportunistic predators, typically feeding on small insects caught on the wing (2) (6).
Reproduction in the dark whiteface involves a brief, tandem flight, in which the male flies while grasping the female by the head with claspers on the tip of the abdomen (6) (7). The pair will then mate on the ground or in surrounding trees, with the male often guarding the female from other males after mating (7). The female dark whiteface will then lay the fertilised eggs by flying over open water and repeatedly dipping the abdomen down, releasing an egg into the water each time. The female of this species can produce over 300 eggs (2) (7).