Photo: C & D Frith
Australian Tropical Rainforest Life
Dragonfly: Neurothemis stigmatizanus
Dragonflies are part of a group of insects called Odonata
Dragonflies and damselflies can fly forwards, sideways and backwards. (Source: Environmental Protection Agency)
Habitat and Distribution:
occur in a wide range of habitats including rainforests throughout the world.
In tropical rainforests they are generally seen along creek beds, tracks and in clearings.
Dragonflies and damselflies are similar - but are easy to tell apart. At rest, a dragonfly holds its wings open, horizontally, while most damselflies rest with their wings more closed and upright. Damselflies are usually smaller and fly more slowly; dragonflies can reach 40kmh. Dragonflies have huge eyes with up to 30 000 facets. (Source: Environmental Protection Agency)
Their bodies are long and slender, with two pairs of semi-transparent wings, often brightly coloured red, blue, orange or brown, well developed for powerful flight.
The giant petelurid dragonfly is one of the world's largest, and lives in the Wet Tropics. It has an 18cm wingspan. About 250-300 million years ago there were giant dragonflies with wingspans over 60 cm. (Source: Environmental Protection Agency)
Both dragonfly and damselfly males have an intriguing method of ensuring paternity. Fertilisation of insect eggs takes place only as they are being laid, the female having stored sperm from various matings. The more males she mates with, the less chance an individual partner has of fathering her young. The penis of the male dragonfly or damselfly, however, is designed to either scoop out any sperm which had been previously deposited or to push it away from the oviduct, before the owner's is placed in prime position for fertilisation. (Source: Environmental Protection Agency)
They rarely travel far from water, in which the females lay their eggs and the subsequent nymphs develop by predating other freshwater dwelling invertebrates and even small fish.
They are sunlight-loving day flying insects that can often be seen darting from one grassy perch to the next, while others hover over vegetation, motionless, save for wing and head movements.
They feed by catching small insects, such as flies, on the wing and their strong jaws are well adapted for dealing with such animal foods.
Most dragonfly and damselfly larvae hunt underwater ambushing or stalking small animals, including tadpoles. The larva captures prey by shooting out an extension of the lower lip at the end of which are two curved, moveable teeth. (Source: Environmental Protection Agency)
Additional Information on 'Perchers': Courtesy Of Damon Ramsey
The 'perchers' of the family Libellulidae are the largest family of dragonflies and in Australia are usually coloured in browns and reds.
They are common around pools of water in disturbed areas, such as clearings and water-filled ditches along the Cape Tribulation road.
An example is Neurothemis stigmatizans (left), which has a large reddish brown body and wings with transparent tips.
Script: Courtesy of Damon Ramsey BSc.(Zool) Biologist Guide