Common Forest Pests

These are some of the major forest pests that the Forest Health section regularly monitors.

Spruce Budworm — The spruce budworm can be one of the most injurious insects found in the forests of Nova Scotia. Forest Health monitors the population of the budworm with surveys during the adult and second instar larval stages, and with an aerial defoliation survey.

Spruce Beetle — This is a very destructive pest of mature and over-mature white and red spruce. Forest Health is studying the beetle populations and tree mortality throughout the province using ground and aerial defoliation surveys.

Hemlock Looper — The hemlock looper is primarily a pest of balsam fir trees. It can cause severe defoliation in one year. Forest Health monitors this insect in the larva, adult, and egg stages, and with a yearly aerial defoliation survey.

Balsam Fir Sawfly — The balsam fir sawfly feeds on balsam fir and white and black spruce. Forest Health has worked with the Canadian Forest Service to develop monitoring methods and control strategies to reduce the damage done by this insect.

Whitemarked Tussock Moth — This insect can defoliate hardwoods, softwoods, and shrubs. Forest Health monitors the population through an adult pheromone trapping system and an overwintering egg mass survey.

Gypsy Moth — This insect feeds on 485 hosts within North America and can be particularly destructive to oak, poplar, and apple. Forest Health monitors gypsy moth populations throughout the province. In the federally regulated areas, pheromone traps are used to monitor population shifts and larval collections are used to monitor the population health. In unregulated areas, pheromone traps, tree skirts, and egg mass searches are used to detect populations.

Seedling Debarking Weevil — This native insect feeds on the bark of softwood seedlings, affecting the establishment and growth of the trees. Mortality levels on planted stock can be very high in some areas where natural regeneration is low. Forest Health can provide traps/lures for predicting expected levels of mortality on those sites before they are planted. Ongoing studies are also being conducted to improve this method.