(Uropetala carovei)

Giant dragonfly
NOTE:  all live insect photographs taken in Otaki,   insects in Garden not photographed

Giant dragonfly 

Maori generally knew the dragonflies as 'kapowai'

They were first identified by Adam While, zoologist on the voyage of H.M.S. Erebus and Terror in 1839-43. This is a representative of archaic and primitive insects with a discontinuous world distribution. There are two sub-species Uropetala carovei carovei of the North Island and Uropetala carovei chiltoni primarily from the South Island.

The dragonflies emerge in the summer, the adults living for 1 to 2 months, although males can live longer, the life influenced by the degree of exposure and climate. They have a wingspan of some 125 mm.

Males are the most frequently seen because they emerge before the females, the females disappear for laying of the eggs, and because the females are damaged during egg laying, they die sooner. The insects do not migrate far from their feeding grounds (wet or swampy places). The females deposit their eggs just below the water level amongst moss, liverwort and other bog vegetation. 6 to 10 elongated eggs are attached separately to subterranean stems approx. 25 mm below the surface of the water. Each egg is some 1.4 mm long and 0.55 mm wide, white when laid, but quickly turning brown. They take 21-25 days to hatch.

The pronymph (1st instar) is contained within the egg. The nymph must emerge within some 30 seconds of the egg rupture as it cannot walk, breathe or feed in this stage. 1.7 mm long at emergence, it grows through 15 instars to 40-50 mm long over a period of 5 to 7 years. Before emergence the nymphs go to the tops of the burrows above the water line. They emerge around dawn and move a short distance from the burrow entrance and ascend a tree trunk or suitable vegetation, the exuviae (exoskeleton) being often found clinging to vegetation

The nymphs live in spring fed swampy or boggy areas where there is constant and permanent seepages of clear water. Water flow is never quick. The last instar has burrows down 300 to 700 mm deep and 30 mm in diameter. A chamber exists with the nympha embedded in fine silt and partly in the clear water above.. The earliest instars are found just below water level. Burrows were always kept clear and soil from collapsed sections and expanded burrows is excavated into a small pile at the tunnel entrance. Only one nymph is found in each burrow.

Final instar nymph from which adult has emerged F

The shape of the burrow is thought to be a response to kiwi predation. The burrow turns up, whereas the kiwi beak turns down - a response to natural selection.

Nymphs move sluggishly. They emerge in the evening after clearing obstructions from the burrow, and remain still at the entrance, waiting for nocturnal insects to come within catching distance. They never move far from the entrance.

Their main enemies are other nymphs. Early instars feed on soil organisms, worms, nematodes etc. Later instars feed on ground insects.

Within the Garden there is a major habitat in Nursery Glen and probably breeds along Puketea Stream. Glow worms probably form part of their diet as these are prevalent in its habitat locality.

The definitive reference is L. S. Woolfe (1953) 'A Study of the Genus Uropetala Selys' from the Transactions of the Royal Society of New Zealand 80:245-275( pdf file). The late Bill Winstanley Victoria University (Otari guide) has also completed specialised studies (partly in the Garden).

A Canadian file can be viewed of the emergence of an adult of one of their dragonfly species. Click. Fascinating