Alaska Forest Health Observations's Journal

July 28, 2021

Yellow-horned horntail (Urocerus flavicornis)

It's that time of year when the yellow-horned horntails are emerging but don't let their looks deceive you, they are gentle giants! Horntails are related to wasps but cannot sting. Instead, that long projection on the back of the females is called an ovipositor, which they use to lay their eggs beneath the bark of dying or freshly cut trees. Some key features to help you identify a yellow-horned horntail are 1 - long, bright yellow antennae, 2- bright yellow eyes, and 3 - a tube-like body shape. Check out the photo below to see the features of our local yellow-horned horntail.

The yellow-horned horntail is a natural part of our forest ecosystem here in Alaska but is frequently mistaken for the Asian giant hornet (AGH) due to its size and bright striping. AGH has not been found in Alaska, but we do appreciate that folks are keeping an eye out for exotic organisms.

Posted on July 28, 2021 20:54 by awenninger awenninger | 1 comment | Leave a comment

July 27, 2021

Needle Rust Fungi

Orange-tipped trees? Rust fungi are coming out in full force this July, bolstered by the wet June weather. Many rusts have multiple host plants & 5 annual spore stages! Trees can tolerate needle rust damage. Learn more at #ForestHealth #AlaskaForestHealth

Posted on July 27, 2021 16:15 by awenninger awenninger | 0 comments | Leave a comment

July 21, 2021

Western Blackheaded Budworm Outbreak in Southeast AK

There is a western blackhead budworm outbreak happening in parts of SE Alaska. The caterpillars feed on new hemlock growth causing reddish tips and an abundance of caterpillar Pile of poo raining down from above, littering the plants below. #AlaskaForestHealth

Posted on July 21, 2021 16:22 by awenninger awenninger | 0 comments | Leave a comment

November 13, 2020

Zombie Virus (Baculoviridae)

Did you know that caterpillars can become zombies- even when it’s not Spooky Season? Caterpillars can suffer from a “zombie virus” (Baculoviridae) that forces them to climb, like zombies, to the tops of branches as they liquefy from the inside out! #AlaskaForestHealth
Posted on November 13, 2020 23:28 by interiorskb interiorskb | 0 comments | Leave a comment

October 16, 2020

Humongous Fungus - Honey Mushrooms!

Honey mushrooms from the fungus Armillaria can emerge in clumps from the trees and roots they infect. Some large genetically-related clumps have been named the "Humongous Fungus," considered among the largest living organisms on earth! #AlaskaForestHealth

Posted on October 16, 2020 16:01 by awenninger awenninger | 0 comments | Leave a comment

October 15, 2020

Spruce aphids -- Elatobium abietinum

Most forest creatures are winding down for winter, but spruce aphids are just getting started! Forest Health Protection surveyed for this invasive insect which is found thru-out SE Alaska & parts of the Kenai Peninsula. #alaskaforesthealth

Posted on October 15, 2020 22:01 by awenninger awenninger | 0 comments | Leave a comment

Sirococcus Shoot Blight on Hemlock

While not everyone enjoyed the rainy summer in SE Alaska, the fungus that kills hemlock shoots certainly did! Look for it and you shall see it! Learn more about this disease of western and mountain hemlocks at #AlaskaForestHealth #SirococcusShootBlight

Posted on October 15, 2020 21:59 by awenninger awenninger | 0 comments | Leave a comment

September 29, 2020

Spruce beetle -- time to process your firewood!

With cooler temperatures approaching, it's time to start processing your dead spruce into firewood. Processing recently killed & attacked trees now can reduce the spread of spruce beetles to new trees next spring. Visit for more info! #AlaskaForestHealth

Posted on September 29, 2020 15:41 by awenninger awenninger | 0 comments | Leave a comment

September 16, 2020

Foliar tar spot fungus (Rhytisma arbuti) on rusty menziesia

Have you seen black spots on false azalea/rusty menziesia? Plentiful rain in SE Alaska has led to an abundance of the foliar tar spot fungus (Rhytisma arbuti). It doesn’t do much damage since it occurs after seedset. For more information visit:

Posted on September 16, 2020 15:49 by awenninger awenninger | 0 comments | Leave a comment

Spruce beetle update (Dendroctonus rufipennis)

The Mat-Su region continues to experience extensive spruce tree mortality due to a spruce beetle outbreak. #AKForestHealth scientists from Anchorage & Fairbanks visited the region to view the area & discuss the health of the forests. For more information, visit

Posted on September 16, 2020 15:37 by awenninger awenninger | 0 comments | Leave a comment