The venom of a native Australian caterpillar contains compounds that could be used in medicines and pest control, new analysis has found.
Caterpillars of the mottled cup moth, commonly found in eastern Australia, have a complex venom made up of 151 separate toxins, according to new research published in the journal PNAS.
Dr Andrew Walker of the University of Queensland, who is the study’s first author, explained the caterpillar has clusters of sharp stinging spines that it displays when disturbed.
“It tucks away its spines when it doesn’t think it needs them,” he said. “We think this is so that it preserves the venom.
“If you just lightly brush up against one, you will get a very noticeable envenomation,” Walker said. The caterpillar’s spines inject liquid venom into anything that contacts it, resulting in a sharp or burning pain similar to a bee sting.
The scientific name for the caterpillar, Doratifera vulnerans, means “bearer of gifts of wounds”.
Of particular interest among the 151 toxins identified, which were all made of peptides, was a compound called cecropin, which kills bacteria and parasites by disrupting their cell membranes.
The scientists also found it was the main compound responsible for the pain the caterpillar’s venom elicits. Research is under way into whether the compound, which is also present in non-venomous caterpillars, could be used for its antimicrobial properties.
Another peptide present in the venom, known as DV33, was able to inhibit the growth of the barber’s pole worm, a common parasite found in sheep. The compound did not seem to have any adverse effects on the cells of mammals, so could potentially be used in agriculture.
“It has a molecular structure … very similar to a lot of the spider venom peptides that we know are quite useful for treating diseases,” Walker said.
The caterpillar’s venomous spines are thought to have evolved as a defence against predation by birds and other animals.
“Caterpillars are really just little eating machines, so they’re these vulnerable bags of very nutritious fat and proteins,” Walker said.
The mottled cup moth caterpillars have bright warning colours to advertise their venom to predators: they are typically green, red or brown in appearance.
The venoms used by animals as defences against predators were previously thought to to be simple in composition, Walker said.
“We weren’t expecting to find a huge number of different kinds [of peptides].”
The function of many of the compounds identified in the venom is still unclear. “We know that they have these structures to suggest that they might interact with the nervous system or with other components,” Walker said.
The researchers hope to test on a larger scale the effects of some of the identified toxins.
