Zombie caterpillars on death march

Tuesday 1st August 2017

Zombie caterpillars are on a relentless march to their deaths on a Lancashire moss...

The skins of the caterpillars have been discovered at the top of small bushes on our Winmarleigh Moss Nature Reserve, near Garstang.

It means the caterpillar is infected by a microorganism, climbs to the top of the plant and then dies. The caterpillar is driven by the baculovirus which then bursts out of the corpse to seek victims below.

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

“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. 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.”

Research is proving that the baculovirus actually affects the way the zombie insects respond to light, making them climb to higher and more dangerous places and when they get there they die.

Oak eggar moths are named because of their acorn-like cocoon, they grow into reddish brown moths and males fly during the day.

The Wildlife Trust owns Winmarleigh Moss and Chris is hoping to transfer the large heath butterfly to other areas where it is extinct.

The Trust successfully moved butterflies to Heysham Moss three years ago, but the project has been jeopardised by arsonists who caused a huge fire.