While some insects are beneficial, others are more of a nuisance and cause irreparable damage to tree populations. To provide proper tree care, learn how to identify and combat common Alaskan pests.

3 Pests That Harm Trees in Alaska

1. Birch Aphid

Birch aphids are small, green, pear-shaped insects with long, slender legs. Notorious for their quick reproduction, they can develop into a full-blown infestation within weeks. They’re often found on the underside of leaves, where they suck sap from the plant.

While a small aphid population isn't enough to cause significant damage, large infestations can deplete a tree's nutrients, causing leaf curling, wilting, and even dieback.

Additionally, aphids leave behind a substance known as honeydew, which can lead to sooty mold growth and attract other unwanted pests such as flies and wasps.

2. Spruce Beetle

Spruce beetles are approximately a quarter inch in length and have dark brown, cylindrical bodies with small, black heads. They’re typically found beneath the bark of Sitka, white, and Lutz spruce trees, where they bore inside to lay their eggs before flying away to find a new host.

Because spruce beetles lay hundreds of eggs, they can quickly destroy a tree from the inside out. The most noticeable symptom of a spruce beetle infestation is the change in needle color—the leaves will transition from green to yellow to red before dropping off completely. Applying registered insecticides can reduce or prevent spruce beetle infestations.

3. Wood Wasps

Wood wasps are large flying insects with elongated black bodies and prominent orange stripes. Females bore into wood and lay hundreds of eggs while simultaneously injecting the tree with a fungus.

Once the larvae hatch, they chew through the wood and leave behind large exit holes as they grow in size and emerge from the tree. Infestations of wood wasps can quickly weaken the structure of a tree and eventually kill it.

 

If you have a pest infestation, contact the knowledgeable team at Carlos Tree Service in Anchorage, AK. Since 1993, their team of arborists has provided expert tree care to help prevent and reduce infestations, including trimming, removal, and insect control. Contact them today at (907) 522-6049 to schedule a consultation, or visit their website to learn more about their tree care services.