The larva of the banded demoiselle occurs among the roots and lower reaches of aquatic plants, usually close to the bottom of the water column. Active mainly at night (3), the larvae are effective 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 (5). Larval development takes around two years in the banded demoiselle, and the larva overwinters twice in the mud at the bottom of the river or pond (3). When it is ready to emerge as an adult, the larva will often travel up to 100 metres out of the water, and typically complete its emergence in a shrub or tree (3).
After emergence, the adult banded demoiselle takes seven to ten days to mature, and the flight period of the adult is between May and the end of September (2) (4). The male banded demoiselle will establish a territory around a suitable egg-laying site, which usually includes abundant vegetation protruding from the water (4). The male may actively court females with a fluttering display flight (3), and then lead them to a suitable egg-laying site (5). After mating, the female will oviposit alone, often placing the eggs into the tissues of submerged vegetation (4). The eggs take around 14 days to hatch (3).