Australia's Largest Insects

The recent aquisition of a truly Giant Stick Insect has prompted this bit of "crowing". Australia's largest insects are to be found in the general vicinity of Kuranda.

But first we have to establish what we mean by "largest". In this sense I am using the term to describe the "longest" and "heaviest" of Australian insects.

Australia's longest insect is the Gargantuan Stick insect, Ctenomorpha gargantua Brock and Hasenpusch.

It was a rather excited Margit who phoned when the giant above hurtled its way into her garden and lit of the wall of her patio. She attempted to feed it but found it dead in a day or two.
The female of the Gargantuan Stick Insect above measured approximately 56 cm from the outstretched tip of the foreleg to the end of the flag-like cercus. It actually shrank a bit after it dried out. It was found on the Atherton Tableland.

Above we see it barely fitting in an insect drawer! The stick insect alongside it is the rather common and large Wuelfing's Stick Insect, Acrophylla wuelfingi Redtenbacher. This insect is known to most northern gardeners who often find it on a variety of fruit trees. The body length of the Acrophylla above measures 21.2 cm.

The world's longest insect is also a stick insect. It is Phobaeticus chani Bragg, a species from the rainforests of Borneo and named after a friend, Datuk Chew Lun Chan. The one with the record measured 56.7 cm. BUT in their Guide to Australian Stick insects, Brock and Hasenpusch illustrate a Kuranda resident holding a female of a specimen reputed to be even larger. He measured it at 61.5 cm long. So had this specimen been kept, it would have been the record holder for the world's longest insect. Records are made to be broken. Sorry Datuk!

The heaviest insect in Australia is actually a cockroach, the Burrowing cockroach, Macropanesthia rhinoceros Saussure, described long ago in 1895 from Queensland. A number of disjunct populations are known of this species in the Australian tropics.

Adults of this cockroach can weigh more than 30 gr.

The Giant Burrowing Cockroach is like a miniature bulldozer. It lives in habitats where the soil is sandy. It establishes a burrow system and drags suitable leaves and and seeds to feed its young which are protected by the mother and live in the burrows. Adults can survive for 5 years or so and are interesting pets that can be kept in plastic containers and fed on muesli. They require little or no water.

In the autumn, males emerge and look for females are often seen crossing roads. To my horror a fellow living in the Mt Garnet area, where the species is common, told me he "collects them for his chooks!"

The "rhinoceros" part of the name of this insects is appropriate. It uses the scoop-like portion of the thorax to dig in sandy soils. The stout, spiny legs are very strong and well suited to digging. Beneath the thorax are a pair of eyes and short antennae. A remarkable insect. (As a cockroach it is a great ambassador- it is clean, disease free and does not produce any disagreeable odours.)