Knowledgebase
Pests on pine tree #871520
Asked June 04, 2024, 12:24 PM EDT
We are new homeowners in our second spring with our two pine trees in the backyard and one has noticeable pests on about 1/3-1/2 of the branches but we've noticed it's spread a bit to the other tree too. We think they are woolly aphids. I stopped by a garden center and showed them the attached pictures and was told we are past the point of being able to spray them and would need to do a soil-based systematic treatment but that they probably wouldn't kill amore mature unless something else was also impacting the health of the tree. They said we could do a more preventive spray early next Spring but are past that point currently. We want to protect the health of the only trees on our property and prefer to treat it as effectively but organically as possible. What do you recommend? We have an arborist coming to do a free consultation this week as well, but are hoping an objective (non-financially motivated) perspective will be helpful. Thank you for your time and expertise.
Larimer County Colorado
Expert Response
I think these are actually pine bark aphids, which do have this cottony coating. But all aphids are very similar to each other and can be treated with numerous ways.
https://yardandgarden.extension.iastate.edu/article/2003/5-16-2003/aphids.html
From the article linked above, control includes:
The least toxic, lowest impact control method is to use a forceful water spray to dislodge aphids from host trees. Thoroughly spray infested plants parts (e.g. foliage, stems) with sufficient pressure to knock the insects off the host, but not injure the host plant. You must repeat this type of application because there is no residual effect. Another low impact control option is insecticidal soap, which is available from garden centers, hardware stores, and department stores under various trade names. Look for a product that lists as the active ingredient potassium or sodium salts of fatty acids. Horticultural oil is also an effective treatment material against aphids. Traditional insecticides used in the home landscape for aphid control on conifers include Isotox, Malathion, and Sevin.
