Ues &pes garden
Dashing and darting about, these colourful dragonflies are useful insects to have in the garden, writes LEONARD CRONIN
Dragonflies epitomise our long, hot summer days, and in these times of climate change and species extinctions it is comforting to know that one of our most common summer visitors has been around for more than 300 million years. Outliving the dinosaurs and even managing to coexist with humans, dragonflies are perfectly adapted to meet the dramatic challenges of an evolving planet.
These four-winged insects seem to materialise out of nowhere, hang perfectly still in mid-air, then dart away in the blink of an eye. One of our most common and conspicuous species is the fiery skimmer, aptly named for the brilliant red abdomen of the male. Yet the flying form we are so familiar with is a brief interlude in the lifespan of an insect that lives mostly under water.
Dragonflies spend up to three years as aquatic larvae, feeding on tadpoles, insects and small fish in freshwater ponds. Propelling itself along by expelling jets of water, this fierce hunter has an elongated lower lip in the form of a hydraulic grabber, which shoots out from beneath its head to harpoon small aquatic creatures with two fangs. Fully grown at around 2cm long, the larvae climb out of the water and metamorphose into their adult flying form. Male fiery skimmers attain their brilliant red colour over the next few days, while females remain brownish yellow.
The fastest flying insects on Earth, dragonflies reach speeds up to 70kph, flitting forwards, backwards and sideways, catching mosquitoes, flies and other flying insects. But their main role in their month-long adult phase is to find and mate as often as possible.
Dragonflies are great to have around your garden, as they devour mosquito wrigglers, and pests such as white cabbage butterflies and other flying insects. They will take up residence provided you have a permanent water supply containing suitable food for the larvae. You can inoculate your garden pond with aquatic creatures for larvae to eat by adding a bottleful of water from a local pond.
Len gardens in the Northern Rivers, New South Wales