Forest & Grassland Health

Birch Leaf Roller

Birch Leaf Roller 

Distinguishing between mines constructed by AMBLM (yellow-brown mines fill with frass) and LBLE (red
Mines of amber-marked birch leafminer (yellow-brown with frass) and late birch leaf edgeminer (reddish without frass).

 

Caloptilia strictella (Walker) 
Caloptilia alnivorella (Chambers) 
Epinotia solandriana (Linnaeus) 

 

Host(s) in Alaska: birch, alder, aspen, cottonwood, and willow.

Habitat(s): birch leaf tissue

Damage: Bud and leaf feeding damage, which can cause leaves to brown and drop prematurely. Repeated heavy infestation can cause branch dieback and mortality. ‚Äč

Click on the image for a larger version.

AMBLM ovipositing on a leaf

Amber-marked birch leafminer ovipositing on a leaf.

 

AMBLM adult roughly 4-5 mm in length

Amber-marked birch leafminer adult roughly 4-5 mm in length.

AMBLM mines in Fairbanks birch

Amber-marked birch leafminer mines in a birch leaf in Fairbanks.

During outbreaks invasive birch leaf miners can impact >90% of a trees leaves

During outbreaks invasive birch leafminers can impact >90% of a tree's leaves

Current Status (2020 Update)

Due to the pandemic, we were unable to conduct aerial surveys to map birch leaf roller damage. However, Epinotia solandriana was observed throughout Interior and Southcentral Alaska, with 47 observations recorded during ground surveys. Nineteen ground survey observations of Caloptilia spp. were made throughout the Interior, with only 3 observations made in Southcentral.

Birch leaf roller was not mapped during aerial survey in 2019, however 121,000 acres were aerially mapped in 2014 and 330,000 acres were mapped in 2013. Based on ground observations, the frequency (number of affected trees) of birch leaf roller infestations in Interior and Southcentral Alaska has remained relatively constant; however, the intensity (number of leaves per tree) is low. Low intensity infestations are difficult to detect during aerial surveys.

 

Symptoms, Biology & Impacts (from Insects & Diseases of Alaskan Forests)

Birch leaf roller larvae roll leaves and subsequently skeletonize them through feeding, which cause them to curl, brown, and drop prematurely. This can cause branch dieback and occasionally tree mortality. Alaskan birch leaf rollers are univoltine (have one generation per year) and overwinter in the egg stage. Larvae hatch in mid-May to early June and begin feeding in buds and as they develop into later-instars, feed in rolled leaves. Sub-adult instars leave their leaf rolls and pupate in fragile cocoons between the humus layer and the mineral soil. The adults emerge in late-July through August. After mating, eggs are laid singly on the previous year’s twigs, usually on roughened bud stalks. While birch leaf rollers (Epinotia solandriana) are the most common leaf rollers observed on birch, there are other genera, including Clepsis, that are also associated with this host. Drastic and repeated defoliation by these insects can result in minor growth reduction and occasional branch dieback. Leaf roller populations are naturally controlled by adverse weather, parasites, predators, and disease.

For more information and relevant photos, see the birch leaf roller forest health leaflet (webpage and pdf for printing).

 

For more information, please contact Dr. Sydney Brannoch, Entomologist, U.S. Forest Service, sydney.brannoch@usda.gov.





https://www.fs.usda.gov/detailfull/r10/forest-grasslandhealth/?cid=FSEPRD691832&width=full