Caterpillars Exploding From “Zombie Virus” Outbreak


Tom Hale

Senior Journalist

clockAug 3 2017, 19:24 UTC

An oak eggar (Lasiocampa quercus) caterpillar, not in zombie form. Dean Morley/Flickr (CC BY-ND 2.0)

Board up your boards and grab your mini-chainsaw. Caterpillars in Britain are becoming infected with a microorganism that induces a hypnotic zombie-like state, eventually leading to a death so gruesome and ingenious, it could have only been developed by nature.

“It’s like a zombie horror film,” Dr Chris Miller, manager for The Wildlife Trust for Lancashire, Manchester, and North Merseyside’s Mosslands in the UK, said in a statement.


Typically, oak eggar caterpillars stay relatively low and avoid climbing towards light sources to avoid getting eaten by birds and other predators. However, if they have the misfortune of being infected by this baculovirus, it messes with their response to light, causing them to climb to the top of plants in their dazed and confused state.

Their bodies then become a liquefied gloopy mess and pop, thereby spreading the infectious virus to other insects on the plants below and allowing the outbreak to continue. Genius.

A victim post-infection. Courtesy of Lancashire Wildlife Trust

This gruesome infection has been documented before, but Dr Miller has been coming across it more and more on his excursions of the English countryside.


“I was carrying out a large heath butterfly survey on Winmarleigh Moss and noticed a caterpillar hanging from the end of a branch of a small bush,” he said. “Later on I saw another one hanging from a tall blade of grass both were dead but otherwise intact.

“Whilst checking some other branches I noticed small scraps of caterpillar skin on a couple of branches suggesting the two I had seen where not the only ones to be affected. It’s pretty gruesome when you think about it.

“It is really unusual seeing caterpillars high up as they can be eaten by birds. This is a caterpillar of the oak eggar moth which eats heather and bilberry so it is normally hidden in the undergrowth, not at the top of plants.”


Previous scientific work has been carried out on caterpillars, the bizarre baculovirus, and exploding zombie-like states. They discovered that it’s all to do with one specific gene of the virus. However, its ability to change the behavior of an another is still a mystery.

Nevertheless, many viruses rely on controlling their host's behavior to complete their life cycles. When many mammals are infected with the Rabies virus, for example, they behave extremely aggressively. This raises the chance of them biting or scratching another animal and therefore spreads the virus even further.

Damn, nature.

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