Bark beetles could threaten drought-stressed B.C. timber

KAMLOOPS – A B.C. government entomologist in Kamloops says the current drought across most of the southern half of the province is stressing timber across the Interior.

Lorraine Maclauchlan says photosynthesis drops when water is scarce, making trees more vulnerable to damaging attacks from insects such as bark beetles.

The beetles bore through bark and munch on the nutrient-carrying layer just underneath, so Maclauchlan says trees use resin as a defence, pumping out the sticky fluid in order to flush away attacking insects.

But without water, trees can't produce enough resin to defend themselves.

Maclauchlan says healthy, standing timber should not suffer an immediate impact from this year's drought but warns the lack of water could have a cumulative effect.

She says a sustained drought over a number of years could allow populations of bugs such as mountain pine beetles to build to potentially dangerous levels.