Expert: Jim Hyland - 6/24/2009

Question
we just discovered a borer in our black locust trees  the trees are young, 4 to 5 years old  i have searched articles on-line to find a treatment-lindane emulsion and carbaryl  where can i purchase these chemicals or what do you suggest as treatment   we have approx 6 young trees (the 2 oldest are infected), planted them because of their fast growth  we live in upstate New York   Thank you for you time and help

Answer
A good  spray for borers is one called Merit or Onyx. These are sprayed on the trunk and are absorbed into the wood killing the borer. A soil applied insecticide that should work is Bayer Advanced Tree and Shrub Insect control. This is applied to the soil and the roots transport it into the trees system killing any insect attacking the tree. It is good for large trees where you can not reach the trunk. Here is a web link to this product--Check with your local nursery for these products. http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html
Usually borers attack trees under stress so I would recommend that you fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. This will increase the health of the tree.