Pine Shoot Beetles Infest Red Pines in Laurel Creek Conservation Area

by John Brouwer

A logging operation is currently underway in the Laurel Creek Conservation Area to remove infested red pines in order to control the spread of the pine shoot beetle infestation. Two hectares of severely infected pines at the north end are being removed and in a surrounding nine hectare area pines are being thinned out. As there is no biological or chemical control measure for this beetle, removal of infested trees is considered the only alternative. The logging operation should be completed before winter. Information is available on the Grand River Conservation Authority website.

The pine shoot beetle is native to Europe, North Africa, and Asia and is assumed to have hitched a ride to North America in imported wood in the late 1980s. The recent mild winters have resulted in a significant increase in infestations. This makes our red pines early victim of globalization and climate change.

The beetle attacks the trees in 2 ways:

  • Adults attack 1-3 year old healthy shoots by tunneling in the pith towards the tip, resulting in shoot death.
  • Adults bore under the bark of the main stem of the tree, construct a brood chamber, mate and lay eggs. Developing larvae then feed on the cambium resulting in tree death by girdling.

The conservation authority intends to replant the severely affected area with native hardwoods such as sugar maple, red oak, black cherry, basswood, and dogwood. Where thinning is undertaken it is expected that the natural understory of hardwoods will regenerate on their own. The replanting is expected to cost up to $25,000.

The GRCA website engages in a bit of revisionist history when it notes that these non-native pines were planted in Laurel Creek in the 1960s and 79s because they were thought to do well in this area. It now concludes that this was inappropriate because the pines deteriorate after 20 years.

However pine trees were planted in numerous Carolinian fields in the 1960s and 70s to provide a faster way to regenerate hardwood forests. Pines grow quickly, can compete and shade out grasses and then provide the shade required for the native hardwoods to establish themselves in the understory. The problem at Laurel Creek is that the GRCA never thinned the pines or planted the native hardwood seedlings in the 1980's. The hardwoods would have grown through the canopy and displaced the pines about now if the GRCA had undertaken proper forestry practices in the 1980s and 90s. It's not quite fair to accuse the earlier foresters of not understanding what they were doing as a cover up for current bad forestry practices.

At Beaver Creek we have a few red pines. I don't know whether the beetle has managed to cross the road. But we should be careful about picking up pine wood across the road and bringing it into the co-op.

November 2007