New-to-science stick insect is the heaviest ever found in Australia

A newly named species of giant stick insect found in Australia’s Wet Tropics rainforests is thought to be the heaviest insect ever found on the continent.

Acrophylla alta weighs 44 grams, around the same as a golf ball, and is approximately 40 centimetres long. Only two female specimens have been collected so far, while a third individual was photographed but released by amazed locals.

Although the genus of these insects has been known since 1835, the species has remained undiscovered by science until now, probably because of its habitat, says Angus Emmott at James Cook University in Townsville, Australia.

The Wet Tropics in north-east Australia are a true wilderness, covered in cool rainforest and home to other unusual animals like tree kangaroos.

So far, Acrophylla alta has only been found on mountain ranges with an altitude above 900 metres and in tree canopies up to 60 metres above the ground, near Millaa Millaa and Mount Hypipamee, both in Far North Queensland.

The species name alta, meaning high, refers to both the altitude of the forests where the insect lives and the height of the forest trees it frequents.

“It’s got quite substantial wings, but it can only sort of use them for gliding down to the ground, because it’s got such a bulky body as well,” says Emmott.

Whether or not it is rare is currently unknown. “Because it’s up in the canopy, we really don’t know,” says Emmott. “It’s restricted to a small area of high-altitude rainforest and it lives high in the canopy, so, unless you get a cyclone or a bird bringing one down, very few people get to see them.”

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