The current outbreak cannot be managed on a landscape level due to the abundance of beetles, ecologically sensitive nature of most tamarack stands, unpredictable site accessibility for logging equipment, and low demand for tamarack forest products.
When managing tamarack for timber, regenerate mature or nearly mature tamarack stands before they are infested. Tamarack occurs in both mixed and pure stands and can be regenerated with a variety of methods including clearcut with reserves and seed tree methods. Encourage tree diversity, and don't shy away from promoting tamarack. Eastern larch beetle will generally not attack small-diameter tamarack seedlings and saplings.
Once a stand is infested, there can be substantial mortality over the course of several years. Following the harvest of infested stands, reserve trees left as a seed source will be attacked quickly and have less chance at successfully producing seed. Still, reserving living tamarack seed trees in beetle-damaged stands may allow for at least one cone crop to regenerate the site before seed trees succumb to eastern larch beetle.
So far there is no indication that eastern larch beetles can be managed at the stand level. However, if a landowner does not want to harvest an entire infested stand, a best practice is to cut all visibly infested tamaracks plus several strips of healthy tamarack next to infested tamarack. The goal is to increase light to the forest floor for light-demanding tamarack or release advance regeneration of species such as black spruce or white cedar. Strips should be at least 200 feet wide to favor tamarack regeneration. Cut trees when the ground is frozen, and remove and process into lumber or chips before spring. Whenever possible, encourage tree diversity by leaving other tree species such as black spruce and cedar on the site, or by planting or aerial seeding with a mixture of site-appropriate trees, including tamarack.
In small harvesting operations on private properties, keep cut logs away from uninfested standing trees to reduce the risk of spreading beetle populations to new areas. Removing the bark makes logs uninhabitable by eastern larch beetle, so bark removal is an option if tamarack wood is to be left on site.
Other sources of information
- Eastern larch beetle - Natural Resources Canada
- Eastern Larch Beetle (fs.fed.us) - U.S Forest Service Insect & Disease Leaflet 175