pitch mass borer
My arborist detected this borer on one of the three blue spruces in my front yard. The trees are over 40 yrs old. They applied a systemic insecticide soil app last fall and are recommending the same application between march and may. The cost is $551.00. Should I continue to pay for this service or just cut them down when the tree dies? I live in Wayne County-Plymouth Michigan
Wayne County Michigan
There are many types of pine pitch moth. The adults resemble yellow jackets. They attack Austrian, eastern white, Scots and Jack pines as well as white, Norway and Colorado blue spruce. Single eggs are laid in the bark of the trees. Larvae tunnel into the cambium of trees, and sap oozes out of the holes in which they feed. Stressed trees are more susceptible. It is difficult to say whether the borers will kill your trees. However, you have to decide on the health of the trees. Colorado blue spruce, which are not native to our area, suffer from several different diseases as they grow older. I suggest that you consult with another certified arborist (you can find one in your area at treesaregood.com, the website of the ISA, the international society of arborists) and have the general health of the trees assessed so you can decide whether not to continue treatment.