The tiny mountain pine beetle is about the size of a grain of rice. ((Natural Resources Canada))

A cold winter has killed off a significant number of mountain pine beetles in Alberta but the province warned Wednesday the war against the bugs is far from over.

The government said the tiny beetles still managed to kill a huge number of trees that must be disposed of and then replanted.

Sustainable Resource Development Minister Mel Knight says the province is also expecting inflights of a new generation of beetles from British Columbia.

Recent surveys show there are still beetle hot spots in Alberta from Whitecourt and Grande Prairie south along the eastern slopes of the Rocky Mountains to the Crowsnest Pass.

Knight says crews will continue fighting the beetles by removing infested trees and by using controlled fires.

The province estimates the beetles threaten up to six million hectares of Alberta forest.