Winter cold not enough to kill pine beetle in Alberta

Mountain pine beetles maintained their grip on Alberta's forests despite cold winter temperatures, the provincial government said today.

Researchers had predicted earlier this year that temperatures plunged low enough for long enough to be deadly to the pest in much of northern Alberta. It takes about 12 consecutive hours of -40 C ambient air temperature to kill the beetle.

Those predictions of a significant kill were based on a scientific model, but officials didn't know for sure until crews headed out into the woods to count beetles at 300 sites across the province in May and June.