How to Identify Woolly Alder Aphids

The woolly alder aphid is a member of the Eriosomatidae family, commonly known as plant lice. Woolly alder aphids feed on the sap of the maple and alder trees. A severe woolly aphid infestation can cause injury to young trees. Learning to identify the signs and symptoms of aphid presence in your trees can prevent this.

Difficulty: Easy

Instructions

1. Learn to identify the woolly alder aphid. These insects can be black or gray and have white wool-like projections or strands that cover the body. They live in colonies.

2. Know the time of year these insects are most prevalent. During the summer to fall seasons, you can see their colonies attached to tree barks. It resembles strung cotton. You can also observe them floating through the air like dandelions when they migrate between the alder and maple trees.

3. Inspect your trees for the presence of honey dew. Aphids feed on sap and excrete this substance, which is waxy, shiny and sticky in appearance. This substance can coat the leaves, bark or area surrounding your trees.

4. Look for black sooty mold on the trees. This mold grows on the honey dew.

5. Check for ant colonies on or about the trees. Ants feed on honey dew and so a presence of ants may signal an aphid infestation.

6. Watch for signs of aphids feeding on your trees. Signs that you have a problem may be twisted, yellowed and curled leaves or poor plant growth.