Forest pests

The Department of Natural Resources continuously evaluates the risk that insect and disease pose to sustainable forest management. When these risks exceed acceptable thresholds, management interventions are designed and implemented within an integrated pest management context. At the end of each year, the department compiles the results of surveys and publishes them in the Summary of Forest Pest Conditions in New Brunswick (PDF 685 KB).

To understand the risk a pest poses to forest values and then determine if it requires a response, is based on a combination of factors, for which some information must be known, predicted or assumed. The more data that can be collected, the more accurate the risk assessment and the more certainty if a response is warranted. It is the role of the Forest Health Section to collect and interpret this information.

Monitoring is on Crown land, industry freeholds and private land. 

Managing NB Crown Forests (PDF 1.0 MB)

Worldwide it is now estimated that over five million species exist, with over one million species identified. Canadian forest hosts about 55,000 species. Very few are major forest pests and those that will vary from province to province based on forest-type and eco-regions. A few of the native species that the department keeps an active watch over include:

• spruce budworm
• hemlock looper
• spruce beetle
• white pine weevil
• spruce sawfly
• cedar leafminer

Pathogens are organisms that cause disease to their host such as fungi, viruses and bacteria. They can be spread from tree to tree by animals, move through the air or water, or even be spread on the boots of humans. Pathogens can be challenging to identify, often requiring microscopes or genetic testing to confirm species. Many of these organisms can lie dormant or persist at low levels until conditions are favorable for rapid spread. The conditions are often environmental and hard to predict, making it challenging to assess risk conditions. Some of the common pathogens on the province’s watch list include:

• armillaria 
• needle casts, rusts and blights

In today's global economy, there is an increased risk of the introduction of non-native pests. Some of these pests may pose a direct threat to forest and natural ecosystems. With the increasing role of plant health and quarantine issues in international trade; they are also an indirect threat to the export and domestic movement of forest products.

New Brunswick has numerous potential introduction pathways. Bordering with three provinces, the state of Maine and containing a large port-of-call for shipping containers in Saint John, the province is a transportation corridor. The Canadian Food Inspection Agency is the primary agency responsible for monitoring and regulating invasive species in Canada. As such, it is their role to monitor for the potential import of harmful pests through these pathways and to identify and regulate new introductions. A list of regulated species and areas, and materials that are prohibited from moving from these regulated areas (e.g. firewood) can be found on their website.

 Some of the species currently monitored include:

• emerald ash borer
• browntail moth
• hemlock woolly adelgid
• brown spruce longhorn beetle
• oak wilt disease
• lymantria dispar asiatica

Before a pest can be assessed for risk, it must be identified. The first line of defense in any forest pest management program is effective detection. The department uses the latest tools and monitoring systems. Monitoring helps determine the presence or absence of pests but also allows the measurement of changes in populations over time to help understand if risk levels are changing.

In some scenarios, the risk posed by a pest is greater than acceptable to one or more of the forest values. The goal is to keep the pest populations below specified thresholds which can cause undesirable levels of damage. When this occurs, preventative, suppressive or regulatory controls may be put in place.

This may include the use of:

• mechanical (direct removal of a pest)
• biological (parasitoids, viruses, bacteria, fungi)
• synthetic insecticides (registered chemicals and biologicals)

The department works with all levels of government, researchers, universities, industry and special interest groups to identify the best available control options and ensure that they are biologically and economically sound, and socially acceptable. The control options identified not only control pest populations and reduced levels of expected insect damage, but they also encourage natural enemies and, where possible, reduce the need for registered insecticides.

Once control and treatment options have been evaluated, a plan is formulated identifying areas at greatest risk and the resources that will be required.

Ground surveys typically include monitoring pre- and post-treatment insect populations and damage levels in both treated and untreated areas. Aerial surveys provide an overall view of the distribution and severity of defoliation within treated areas in comparison to levels that were forecast. Statistical analyses are conducted to measure treatment effects (for example, insect mortality, foliage protection) to assess and identify the most effective protection tools that will improve future pest management decisions.

You can check the historical database representing early pesticide use in New Brunswick.

Spruce budworm management in New Brunswick