Gaudy grasshoppers have scientists jumping out of their skins

JFS employee Royce Namarnyilk in the field with two Leichhardt’s grasshoppers that shed their skin to reveal their gaudy colours. PHOTO: ROBERT (GREENIE) THORNE.

THE Leichhardt’s grasshopper is a pyrgomorph (or ‘gaudy grasshopper’ – and if you look at the photo below you’ll see why) that is endemic to the sandstone heath communities of Kakadu and other areas of the Top End. 

A recent trip to the Nourlangie region of Kakadu by Supervising Scientist Jabiru Field Station (JFS) staff in search of bushtucker led to an unexpected meeting of two fine – and very ‘gaudy’ – Leichhardt’s specimens. 

The grasshopper, once thought to be extinct, is not only exceedingly rare, but is only seen in the wet season and only on two species of shrub. The eggs of the grasshopper lie dormant through the wet season and hatch when the dry weather comes. The nymphs go through various stages, all on the one plant, until they reach full grasshopper-hood and shed their skin multiple times revealing their brilliant colours. 

Gundjeihmi call the grasshopper Alyurr. They are the children of Barrginj and Namarrgon’s ‘children of Namagon (lightning man)’ children. At the end of the dry season Alyurr call to their father to bring the rain. Namarrgon uses his axe to split the clouds in the sky and bring the spectacular thunder storms of the Top End wet season. 

The remoteness of the Leichhardt’s grasshopper habitat has made it difficult to study and also to protect. Even though it is quite rare, the grasshopper isn’t able to be covered by Endangered Species Legislation because we don’t fully understand its basic distribution, biology and ecology.

One of the Leichhardt's grasshoppers, known locally as 'Alyurr'. PHOTO: ROBERT (GREENIE) THORNE.

Reproduced courtesy of The Monitor, Supervising Scientist’s ARR monitoring update.

Supervising Scientist is a branch of the Australian Government Department of Environment’s Science Division. The organisation was established in 1978 to conduct research on the impact of uranium mining on the environment of the Alligator Rivers Region and to supervise the regulation of uranium mining in the region on behalf of the Commonwealth Government. To assist the Supervising Scientist perform this role, the Environmental Research Institute of the Supervising Scientist (eriss) and the Office of the Supervising Scientist (oss) were established.