Backpacker's 'frightening' discovery exposes Australia's 'unspoken rule'

Aussies were quick to remind the man to 'look but don't touch'.

Visitors to Australia are continually stunned by our diverse flora and fauna. But even on his sixth time holidaying down under, a German backpacker was left "frightened" after stumbling upon a strange sight on a nature trail.

Although a "beautiful" place to visit, the tourist, who was visiting Victoria recently, pointed out that "everything is somehow much bigger here" referring to our selection of native reptiles, bugs and animals, and while walking through the Yarra Ranges National Park spotted something unusual on the ground.

"I came across these huge dead larvae on a hike. I've never seen anything like it before," the backpacker, shared on Reddit. "Does anyone know what species they belong to or have aliens landed here?" he continued and revealed that he discovered the critters while on the way to the popular Keppel Lookout near Marysville.

Spitfire larvae or sawfly dead on ground in Yarra Rangers National Park
The deceased spitfire bugs were discovered by a German backpacker who was visiting the Yarra Rangers National Park in Victoria. Source: Reddit

Unusual critters identified

The creatures were identified by entomologist Dr Andrew Mitchell as "spitfires" or sawfly larvae, which are primitive wasps commonly mistaken as caterpillars. And while they're often thought of as venomous given their moniker, spitfire bugs are harmless to people and animals.

"They feed on eucalypts and related native plants like bottlebrushes and tea trees," Dr Mitchell, a scientist at the Australian Museum told Yahoo News Australia. "They don't sting. Apart from regurgitating on you (a brown, possibly irritating liquid derived from their food plants), they are completely harmless."

Tourists should 'look but don't touch'

Many Aussies recognised the critters, although in the photo they were deceased. Despite being harmless, even when alive, some took the chance to remind visitors of the "unspoken rule" in Australia — to "look but never touch".

Spitfire larvae or sawfly on ground in Yarra Rangers National Park
The tourist said they looked like aliens and were much bigger than what he was used to. Source: Reddit

"Not touching wildlife is always a good idea. Dangerous names just help reinforce that," one person said. "Strongly recommend you do not try to touch or pick it up, another lamented, stressing they are "not joking".

The backpacker said in all the times he's been here that he's "never seen anything like it before" and reassured others that he "still kept a safe distance" even though they were dead.

Dr Mitchell could not confirm what could have killed the group of spitfire larvae but suggested bad weather or other predators could have been to blame. Given they travel in groups and move from one tree to another, someone else on Reddit thought "someone or something" could have killed them while they were travelling.

Spitfire larvae  on tree and sawfly wasp
Spitfires (left) develop into sawflies (right), which is a type of wasp. Source: Getty

What are spitfire or sawfly bugs?

Typically the bugs are black and hairy with yellow tips. Despite their name, they don't spit but the moniker does describe a commonly observed behaviour, which Associate Professor of Biology, Dr Darrell J Kemp, previously explained to Yahoo.

"If disturbed they whip themselves around and regurgitate their foregut contents (usually a soupy mess of part-digested eucalypt foliage). That’s nasty enough to deter most predators I guess," he said.

Dr Mitchell said the critters do have "some interesting traits". "For example, the females can lay fertile eggs without mating," he said.

"They get their name sawfly from the females' ovipositor (egg laying tube) which is serrated allowing them to saw into plants to lay eggs inside where they are protected," he added.

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