Insects and Diseases

IPM technician examining insect under microscope.

Insects and Disease play a critical role in both forested and urban landscaped areas of Alaska.

The impacts on either may overlap, but their role may be more or less significant, depending on the land management objectives for each.  For this reason the science of forest entomology and pathology, although relatively new to Alaska, is an important component to understanding this dynamic overlap and how this will impact the people of Alaska.  In Alaska, our rich natural resources are a cherished commodity whose preservation is in all of our interests.  In order for us to accomplish this goal we must further understand the role that insects and diseases will play in this equation and how we might make well-informed decisions regarding their presence. 

The use of Integrated Pest Management (IPM) control techniques can be an effective and environmentally friendly method for incorporating science into this decision- making equation.  The identification of insects and diseases and determining their status is a critical component to making wise decisions regarding any management options.  There are many IPM options available to homeowners and land managers depending on their management objectives, but the first step is to have a correct identification of the organisms from which to base all further decisions.

Another aspect of the role Insects and Diseases have in Alaska is the increase of Invasive pests (introduced non-indigenous plants, animals and microbes). The threat that these introduced invasive pests may have on our forest resources and urban health is undocumented and unknown.  However, introductions are continuing to occur and the evidence is mounting in other areas of the negative impacts associated with them.  The loss of biodiversity in forest ecosystems and the increase in chemicals necessary to combat introduced pests in urban areas is a reality in much of the lower 48.  Here in Alaska our geographical isolation has given us time to possibly prevent many of the same problems associated with invasive pests that occur in every other state. 

Featured Article

Geometrid moth defoliation and activity on the Kenai Peninsula and South Central Alaska

Article compiled by: Michael Rasy, Janice Chumley, UAF/CES & John Lundquist, USFS, State & Private Forestry & Nathan Lojewski, Chugachmiut Forestry. Updated July, 2011.

What is eating my trees and berries?

An unusual outbreak of insect defoliators is currently occurring in various locations in South Central Alaska including the Matsu Valley and the Kenai Peninsula. Especially severe outbreaks can be seen on various tree and shrub species at the upper reaches of Hiland and Arctic Valley Roads, around Summit Lake, near Homer, and near Seward on the Kenai Peninsula where hundreds of trees have been completely or nearly completely defoliated. A similar outbreak on berry crops was recently reported from Nanwalek on the southern Kenai. If you had looked close enough as the leaves started expanding this spring, you would have seen caterpillars munching on the foliage.

Various insect species (especially geometrid moths) have been collected from affected trees, and the specific insect culprit depends on what plants are affected and where, but the current thinking is that the main causes are the autumnal moth and the Bruce spanworm. Other leaf eating insects are undoubtedly involved also...

Click for Geometrid update FULL TEXT (PDF)

Past Articles

Adult Amber-marked birch leaf miner (Profenusa thomsoni)

Impact of biological control on invasive birch leaf mining sawflies in Alaska

Since birch leaf miners were first introduced into Alaska during the late 1990’s, their presence has been a concern for property owners and the subject of research among scientists. The leafminers have moved beyond their original Anchorage introduction into urban and natural areas surrounding many of our most populated centers, including Fairbanks and the Kenai Peninsula. The leaf mining activity has fluctuated from year to year, but there is still much inquiry into possible pesticides that can be utilized for treatment.

In addition, the birch leaf mining injury in Alaska has been caused by three different species of sawflies (Hymenoptera: Tenthredinidae). Profenusa thomsoni, the amber-marked birch leaf miner, has been the dominant birch leaf miner species of concern over the last several years. However, in recent years Heterarthrus nemoratus, the late birch leaf edge miner, has become more common and even dominant in some areas...

Click here to read more about birch leaf miners

Frequently Asked Questions

Q. What is causing the shiny droplets of sticky liquid that are falling onto my car, deck and house near birch trees?

A. Birch Aphids

More Information on Birch Aphids

Q. My cotoneaster leaves are all rolled and webbed, my plants look terrible! What is causing this and what can I do to stop it?

A. Leaf rollers

Q. There are a lot of large spiders in my crawl space, and I’m concerned that some of them might be poisonous hobo spiders.  What can you tell me about spiders in Alaska?

A. Spider solutions

How you can help

If you have an insect or disease specimen you would like to submit to the IPM program for identification, please fill out this form. You can submit the form in person at our office or online.  Thank you.

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