Beetles threaten to munch their way through North American forests

A troublesome beetle is munching its way through square miles of pine trees in North America, wreaking havoc in an area of forest 10 times larger than previous outbreaks.

The current mountain pine beetle attack amounts to 150,000 square kilometres, well over twice the total surface area of the island of Ireland.

Scientists believe they have the culprit - Dendroctonus ponderosae - cornered however.

Scientists in four Canadian universities led by Prof Joerg Bohlmann of the University of British Columbia have put together the full genome of the beetle, information that may pinpoint new ways to counter its advance through the forests of the Pacific northwest.

Details are published today in the BioMed Central open access journal Genome Biology .

It is an ugly brute and has a lifestyle that involves trees being ganged up on, chewed through and infected with a fungus. It is a north American native so the forestry industry cannot blame an alien species invasion.

Once a beetle lands on a tree it releases odourants - pheromones that attract more beetles until the tree is swarming with them. This helps the spread of a fungus and if that doesn’t do for the tree then beetle larvae will.

Eggs are deposited under the bark and when the larvae emerge they munch away and destroy the tree.

This is only the second beetle species genome to be fully sequenced, after the red flour beetle. Being able to look for important genes opens up the possibility of developing new ways to halt the forest wipeout.

The team are looking for genes that help the beetle break down the tree’s own chemical defences and genes associated with the release of the pheromones, something that might shut down the mass attack by the beetles.