Knowledgebase
Zimmerman pine moth infestation, I think #927214
Asked March 31, 2026, 7:12 PM EDT
Olmsted County Minnesota
Expert Response
Hi Corlis,
Thanks for reaching out. You do not need to send us pictures, but you can verify what you are experiencing here: https://apps.extension.umn.edu/garden/diagnose/plant/evergreen/pine/shootssticky.html (Scroll down to "Zimmerman Pine Moth" section for some pictures). You are welcome to send pictures if you'd like our opinion.
https://hort.extension.wisc.edu/articles/zimmerman-pine-moth/ This article has very helpful information about control. If you are going to use an insecticide, it is recommended to use it in the spring, before the larvae migrate into the tree trunks. You only need to spray the trunks - not branches or foliage.
Your blue spruce should be OK. Make sure to mulch your trees and provide adequate water; trees that are stressed are more susceptible to this pest. (https://extension.entm.purdue.edu/publications/E-40/E-40.html)
If you do use an insecticide, remember to always follow the label directions attached to the container you are using. Labels may change frequently, and the label is the law.
I hope this helps!