Jeff from Pewaukee, Wi writes
Davey has used Permethrin SFR on mature white pine in metro Milwaukee area with questionable effectiveness. What do you recommend for pinne tree borers in the metro Milwaukee area? Thank you
Unfortunately there is no easy solution when it comes to pine beetles/borers. Infected trees should be cut down (before the newly hatched beetles fly out of the trees in the spring/summer) and the wood burned or chipped, while other still healthy trees should be sprayed annually to protect them. Because of the natural boring behavior of the beetle they are protected from topically applied insecticides and systemic insecticides (those injected into the tree or applied as a root drench) have proven ineffective for pine beetle infestations. Healthy trees can be protected before the beetles attack by topically spraying them with either Permethrin SFR or Bifen XTS. The tree should be sprayed from the ground to 15 ft up the trunk to prevent future infestations. You should contact your local cooperative extension office to find out the best time to start spraying in your region.
Answer last updated on: 05/04/2018