Male whitewater rockmaster - diphlebia lestoides — Male whitewater rockmaster| Diphlebia lestoides - Images: Chris Burwell

Dragonflies and damselflies

Learn more about these colourful and attractive animals that are among the best-loved insects.

Overview

Dragonflies and damselflies are among the most charismatic and best-loved insects. Together with butterflies, they are the insect equivalent of birds: many species are colourful and attractive, and most can be identified with relative ease, especially compared with other insect groups.

Dragonflies and damselflies are increasingly popular subjects for nature photographers, but patience and skill are needed to capture the more wary species.

Together, dragonflies and damselflies make up the insect order Odonata. Although they belong to the same order, there is no common name in English that collectively refers to both groups. The more technical term ‘odonates’ can be used to collectively refer to dragonflies and damselflies.

By global standards, Australia has a relatively small fauna of dragonflies and damselflies for its geographic area: a little over 330 species. Queensland has over 235 species, more than any other Australian state or territory.

Identification

The insect order Odonata is subdivided into three suborders. Two suborders occur in Australia; Zygoptera (damselflies), and Anisoptera (dragonflies). The third suborder, Anisozygoptera, contains only four dragonfly-like species found in Asia.

Several features help to distinguish damselflies from dragonflies, but not all of them are definitive. Dragonflies tend to be more robust and stout-bodied, while most damselflies have more slender, elongate bodies. However, some damselflies can be quite stout-bodied.

Unlike most winged insects, dragonflies and damselflies cannot fold their wings flat over their abdomens. When perched, almost all dragonflies have their wings outspread, held flat or angled downwards and forwards. Most damselflies perch with their wings clasped together above the abdomen. There are, however, exceptions to these general ‘rules’. Several species of damselflies rest with their wings fully or partially outspread. Globally, dragonflies of only two genera perch with their wings clasped together. One of these is the Australian genus Cordulephya, aptly named shutwings.

The shape of the wings is a useful feature for distinguishing damselflies from dragonflies, at least in Australia. Damselflies have similar-shaped forewings and hindwings, and all have narrow bases. Dragonflies have dissimilar-shaped wings, with the hindwings having much broader bases than the forewings.

Finally, the position of the eyes is a reliable way to separate the two groups. Damselflies have very widely separated eyes on opposite sides of the head. Dragonflies have larger eyes that either meet in the middle of the head (most Australian species) or are narrowly separated (species in the families Petaluridae and Gomphidae in Queensland).

Blue Skimmer dragonfly - Orthetrum caledonicum — A Blue Skimmer, *Orthetrum caledonicum*, a dragonfly that rests with its wings outspread.
Image: Queensland Museum, Chris Burwell.

Common Bluetail damselfly - Ischnura heterosticta — A Common Bluetail, *Ischnura heterosticta*, a damselfly that rests with its wings clasped together.
Image: Queensland Museum, Chris Burwell.

Common Shutwing dragonfly - Cordulephya pygmaea — A Common Shutwing, *Cordulephya pygmaea*, a dragonfly that rests with its wings clasped together.
Image: Queensland Museum, Chris Burwell.

Golden Flatwing damselfly - Austroargiolestes chrysoides — A Golden Flatwing, *Austroargiolestes chrysoides*, a damselfly that rests with its wings outspread.
Image: Queensland Museum, Chris Burwell.

Dragonflies and damselflies, like butterflies, are one of the few groups of Australian insects where most species can be identified by their colours. Using colour to identify species, however, is complicated by a couple of factors. Firstly, many species are sexually dimorphic, meaning that males and females look different, often dramatically so. Males of many species are easier to identify than females, as they are more brightly coloured. This is particularly the case for damselflies in the family Coenagrionidae and dragonflies in the family Libellulidae. The more sombrely coloured females in these two families can be a challenge to identify.

Secondly, many species change colour as they age. Freshly emerged adults of all species are very pale, and their cuticle (the exoskeleton) may take several hours to harden and develop its colouration. As the adults of many species age, the ground colour of their cuticle changes, particularly in males. In addition, many species develop a powdery, waxy bloom on the surface of the cuticle as they mature. This coating is usually white or pale bluish and is called pruinescence. Finally, very mature adults are often darker and duller-coloured than younger individuals.