Seventy years passed before Leichhardt’s grasshopper was officially ‘rediscovered’ in 1971 by Principal Research Scientist of CSIRO’s Division of Wildlife Research, J. H. Calaby. Calaby had returned to South Alligator River, now protected within Kakadu National Park, to spot a single male nymph on a sandstone pediment.
While Calaby’s find meant that the species was not extinct after all, it remains particularly rare and little studied, with just a few fragile populations sustained by three native species of flowering shrub within the Kakadu and Keep River National Parks.
Bright colouring in insects usually signifies some level of toxicity, as does this species’ tendency to spew a brownish liquid when agitated, but chemical analysis has turned up little evidence that these grasshoppers are harbouring any toxic compounds.
And weirdly enough, the species has no known vertebrate predators, which suggests that rather than being toxic, the brownish spew’s purpose is simply to taste awful. Classic spew.
In 1996, chemists William Kitching and Mary Fletcher from the University of Queensland analysed the species’ host plants to find certain compounds that are associated with bitter-tasting glycoside sugar groups, so they suggested that by feeding on these plants exclusively, the species cements its reputation as a terrible meal.