It is hard to imagine that an insect the size of a grain of rice can destroy thousands of kilometres of trees. Well, it can”t, but millions of these tiny insects can, and are.The tiny mountain pine beetle has been living quite well in a symbiotic relationship with the lodgepole pine forests of west coast British Columbia for eons.However in the last few years something has changed to upset the delicate balance. That change is in the climate.Previously , cold Canadian winters kept the insects numbers and range in check but with climate change, that natural control mechanism is gone.The insects have not only been able to thrive, but to expand their range until the unthinkable happened. A warm wind blew them over the natural barrier of the Rocky Mountains and into the forests of Alberta, and the rest of the country.Along the way they have killed millions of acres of trees in the vital boreal forests and it seems there is simply no stopping them.
The lodgepole pine defends against attack through leaking sticky sap, The pine beetle, the size of a grain of rice tries to get through the sp to the bark underneath while also excreeting pheremones to attract other beetles to aid in attacking the tree. (Photo: 52 Media)
The balance between insect and tree has always been a three way equation. The tree has defences against pine beetle attack, and the insect emits pheromones to attract other beetles to help attack the tree.
Usually attacks were only successful against older trees nearing the end of their life cycle. Beetle numbers were never sufficient to attack vast numbers of trees, nor the younger healthier ones.But the third element in the balance has always been Canada’s cold harsh winters which put the brakes on the beetle population by killing off substantial numbers helping to keep them in check.Global warming has now taken that brake off. In the past decade, the beetles have survived the milder winters and their numbers and range has expanded exponentially.In the early 2000’s the unthinkable happened. A wind blew vast clouds of beetles over the previously impenetrable barrier of the rockies into the pine forests of Alberta. It is now thought the beetle is adapting to attack other species of pine, and is moving eastward with apparently nothing able to stop its advance.With the vital boreal forest under attack, the implications to climate and the survival of many species dependent on thick forests are of great concern.
The Beetles are Coming) hundreds of acres of dead pines, after a year or so the dead needles go from orange to grey before falling off. (Photo: 52 Media)
The film, The Beetles Are Coming will be aired on Canada’s national CBC television network (the Nature of Things) this week. Filmmaker David York says his work was inspired by the book Empire of the Beetle by award-winning journalist Andrew Nikiforuk. The book examines the unprecedented destruction caused by the beetle due to climate change.
David York of 52 media has produced a documentary film called, The Beetles Are Coming. RCI’s Marc Montgomery spoke to him about the film.
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