Birch Leafminer Outbreak - Interior and Southcentral AK

Have you noticed the birch leaves yellowing a bit early this year? Check out this press release from the US Forest Service regarding the current birch leafminer outbreak in Alaska: https://www.fs.usda.gov/detail/r10/news-events/?cid=FSEPRD1057235

FAIRBANKS, Alaska – Aug. 30, 2022 – Birch tree leaves in Interior and Southcentral Alaska have turned brown prematurely due to an ongoing outbreak of two birch leafminer invasive species, the amber-marked birch leafminer and the late birch leaf edgeminer.

As larvae, birch leafminers live in and eat the insides of birch leaves, causing them to turn yellowish-brown and prematurely drop before the fall season. During an outbreak, up to 90 percent of the leaves on a tree can be defoliated. The extensive defoliation by the larvae has resulted in browning birch tops observed in hillsides and along roadways, which has raised concerns about a hastening to fall as well as public concern for the state of birch trees in outbreak areas.

Residents may soon notice large amounts of larvae on the ground near birch trees or collecting on property sitting under birch branches. After summer feeding, birch leafminer larvae drop to the ground, and spend the winter in a cocoon, emerging as adult sawflies the following spring.

Damage by birch leafminer is primarily aesthetic and tree death has not been observed in Alaska so far. Repeated damage, however, can result in declining tree-growth rates and weakened trees that are susceptible to damage by secondary diseases and forest pests.

Forest visitors can help the Forest Service track the birch leafminers by uploading photos, video, or information on sightings or damage to iNaturalist.com, which will automatically be included in the Alaska Forest Health Observations Project, a citizen science project in iNaturalist. More information on the project can be found here.

For more information visit the Forest Health website.

Alaska’s National Forests – where nature, people, and tradition come together. Follow Alaska’s National Forests on Facebook and Twitter. For a wealth of information about the Alaska Region, visit our media toolkit.

Publicado el 31 de agosto de 2022 a las 09:28 PM por awenninger