The hemlock woolly adelgid is a tiny sap-sucking insect that causes widespread death and decline of hemlock trees. Native to Asia and the Pacific Northwest, the species was first discovered in a park in Richmond, VA, United States, in 1951. It initially spread slowly until the late 1980s but began to kill trees by the thousands when it reached natural forests. Since then, it has spread to at least 17 states, from the Smoky Mountains to southern Maine.
Identification
Its primary target is new growth, which makes it easy to spot in early summer or spring. Depending on the season, the following characteristics can help you identify it:
- Spring: Orangey-brown eggs
- Early summer: Tiny reddish-brown crawling insects. They almost resemble pepper sprinkled on the stems.
- Summer: The young insects spin a little white nest, made of a waxy, woolly-looking substance. The small white nodules are visible at the base of the needles along the stems. It is the easiest way to identify the woolly adelgid.
- Fall: During the summer, the woolly adelgid goes dormant. They come back out and start feeding in the fall and over the winter.
Treatment
Once you have identified that one or more of your hemlock trees have woolly adelgid, apply an insecticide to the soil around the tree trunk base. The tree’s root will absorb it and transport it to shoots and needles. The insecticide you buy must have either imidacloprid or dinotefuran. Follow the product’s label to determine the correct quantity for each tree.
Chemicals:
Imidacloprid moves slowly, taking at least a year to reach the top of a large tree. However, one application will protect the tree for at least four years.
Dinotefuran moves through hemlock trees more quickly, making it an ideal choice for large, old trees or those showing decline due to infestation. Dinotefuran protects trees for one to two years.
Imidacloprid moves slowly, taking at least a year to reach the top of a large tree. However, one application will protect the tree for at least four years.
Dinotefuran moves through hemlock trees more quickly, making it an ideal choice for large, old trees or those showing decline due to infestation. Dinotefuran protects trees for one to two years.
Application
Soil drench: Mix the correct amount of product in a bucket of water. Brush away old leaves, needles, and other debris from around the tree, and then pour the solution around the trunk base. Let the solution soak in and the soil surface dry before reentering the treatment area.
Granular: Remove debris from the ground and then spread the correct amount of granules around the tree’s base as close to the trunk as possible. You’ll have to protect people, pets, and wildlife from the granules using a watering can or sprinkler to help the insecticide soak into the soil. You must also cover the treated area with a thin layer of mulch.
Granular: Remove debris from the ground and then spread the correct amount of granules around the tree’s base as close to the trunk as possible. You’ll have to protect people, pets, and wildlife from the granules using a watering can or sprinkler to help the insecticide soak into the soil. You must also cover the treated area with a thin layer of mulch.
About Seacoast Tree Care
Hemlock woolly adelgid is a severe threat to the eastern hemlock species. If your hemlock trees are infected, you must hire professionals to keep your trees healthy. At Seacoast Tree Case, we have a qualified team of certified arborists who will help your trees flourish and thrive in all seasons. Seacoast Tree Care is an expert in complete tree care, preservation, and removal. Call us at 603-431-0101 or 978-225-6644, or drop an email at info@seacoasttreecare.com to know more about how to care for hemlock trees. You can also fill up our contact form, and we will get back to you.
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