Dragonflies and Damselflies
Dragonflies and damselflies can be found in all freshwater habitats in the tropical north Queensland, Cape York and Gulf Savannah regions. From swamps at sea level to crystal clear, fast flowing rainforest streams of the highland rainforests, these primitive insects abound in a variety of sizes and colours.
Dragonflies and damselflies belong to the order “Odonata”, a reference to their large teeth-like mandibles which both adults and larva possess. Dragonflies are a more solidly built than the more frail and delicate-looking damselflies. Their forewings and hindwings differ in shape and when at rest are held flat and at right-angles to their bodies. The wings of damselflies are similar in appearance and when closed are held together above their bodies.
Many species are endemic to Australia.
Dragonflies and damselflies are predators. They feed on mosquitos, gnats and other small flying insects which they take on the wing. Their multi-faceted eyes allow for almost 360-degrees visibility. Therefore they hunt by sight.
Away from the coast and in the upland region, we mainly encounter dragonflies during the warmer months of late spring and summer. Nearer the coast the period of activity may start earlier and last much longer depending on the season.
The life cycle comprises of three development stages, egg, larva and adult. In most species, eggs are laid in water, while a few insert their eggs in the stems of aquatic vegetation. Lava hatch from 6-30 days depending on water temperature. Like the adults the larva are predatory and hunt small, aquatic invertebrates. Once the larva is fully developed it climbs out of the water onto a plant stem, log or stone in preparation for its last stage of metamorphosis.
Dragonflies in the genus Petalura are similar to fossil dragonflies from the Jurassic Period dating back 195-135 million years. The Giant Petaltail, (Petalura ingentissima) is Australia’s largest dragonfly and possibly the world’s largest and/or heaviest. At Warrigal Highland Rainforest Preserve in the Misty Mountains we have seen this species hawking winged termites, many times after a hatch has occurred. Other species regularly encountered in the summer months at Warrigal include Green-striped Darner (Austroaeschna forcipate), Ochre-tipped Darner (Austroaeschna weiski) Blue Riverdamsel (Pseudagrion microcephalum) and many others..
The tropical north Queensland, Cape York and the Gulf Savannah regions have about 180 species that have so far been identified and described. Most dragonflies and damselflies have clear wings and coloured heads, thorax and abdomen. There are however a few species that have brilliantly coloured or patterned wings and short abdomens. The five species of Flutterers that occur in the tropical north Queensland region, all have coloured panels and/or patterns in their wings. One species that inhabits lowland swamps is the Jewel Flutterer (Rhyothemis resplendens). This species has brilliant iridescent, electric blue-black patches in its wings (main image at top of page). The Painted Grasshawk (Neurothemis stigmatizans) and Spotted Grasshawk (Neurothemis olegoneura) also have wing colour
Dragonflies and their larva are sensitive to pollution and habitat modification. A few species have already been listed as ‘of concern’ while several others are already listed as endangered.