KIHITARA REDCOAT DAMSELFLY

Xanthocnemis zealandica

Females of this species are noteworthy for having two colour forms. Naiads are territorial and wave their tails to deter rivals.

Description: Males (above) have bright red abdomens, giving rise to the common name redcoat damselfly. Some females (centre) also have a red abdomen, although the rear end is darker than in males. The second, more common, female colour form is dark on top with yellow sides. Females reach a maximum length of 39mm; males are slightly shorter. Naiads (below) are long and slender with prominent leaf-like gills on the rear end. Damselflies can be differentiated from dragonflies by the way they hold their wings when at rest: damselfly wings in line with the body, dragonfly wings out to the sides.

Habitat and distribution: Associated with pools, lakes, puddles and slow-moving streams, kihitara can tolerate a variety of water conditions from mountain tarns to swamps and brackish coastal pools. Seen from Te Tai Tokerau Northland down to Rakiura Stewart Island, they are typically on the wing between October and mid-March. Rēkohu Chatham Islands is home to a similar-looking related species, Xanthocnemis tuanuii.

Biology: Eggs are usually laid in submerged aquatic plant stems immediately after mating. Males may sometimes guard egg-laying females to deter rival males that might attempt to remove their sperm. The naiads are unusual among the Odonata (dragonflies and damselflies) for exhibiting territorial behaviour. They aggressively defend favoured perches on submerged stems or roots by twisting their bodies and waving their large tail gills; if this display is insufficient deterrence, they may attempt to strike each other with their gills. The naiad phase takes about two years to complete but may take three at higher altitudes. When the adult is ready to emerge, the naiad climbs out of the water on vegetation, the skin splits and the adult eventually pulls itself clear. Both adults and larvae are predators.

Status in Aotearoa: Endemic