The Leichhardt’s grasshopper is a Kakadu icon.

These colourful insects are named after the explorer Ludwig Leichhardt, who reported great numbers of them as he travelled through this area in 1845.

They are only found in a few places – Kakadu, West Arnhem Land, Nitmiluk National Park, and Keep River National Park on the Northern Territory’s western border.

Where to see it

Seeing Leichhardt’s grasshoppers up close requires patience and persistence. They are visible during the tropical summer, although numbers fluctuate significantly each year.

The best place to spot them is on pityrodia bushes in the stone country around the Arnhem Land escarpment. Try the Barrk sandstone walk in the Burrungkuy (Nourlangie) region.

Behaviour

Leichhardt’s grasshoppers are extremely picky about their food. In Kakadu they only eat one thing – the pityrodia bush. It is quite common for a grasshopper to spend its entire one-year lifespan on just a few bushes.

Leichhardt’s grasshoppers scare off potential predators with a chemical defence. When the insects feel threatened, they secrete a smelly brown substance that tastes awful to any animals looking for a snack.

Culture

These insects are a sign of the changing seasons in Kakadu. They come out in October every year to coincide with the build-up and first rains of the monsoon season.

Kundjeyhmi speakers call the grasshoppers ‘alyurr’ and believe they are the children of the Namarrkon lightning man, a powerful creation ancestor. In the build-up to the tropical summer, the alyurr call out to their father, who answers with storms and lightning.

Other names

• Scientific name: Petasida ephippigera