Over the past couple of years, we have dealt with a host of new or unusual issues with pine trees, especially white pines, but also red, Scots and Austrian pines.
PINE BARK BEETLES (Ips calligrapha, others)
These beetles are usually opportunistic pests in Michigan, successfully attacking stressed white pines, but usually not able to attack healthy white pines. But over the past few years, we have seen a number of white pines killed by these beetles, including many pines that did not seem to have pre-existing stress or conditions that would render them susceptible to attack. Once the tree looked discolored or sick, it is usually too late to prevent the tree from dying. However, we do have some preventive insecticides that can be applied by trunk or soil injection.
WHITE PINE WEEVILS
This pest can attack even healthy pines (also spruces) and causes dieback of the top of the tree. This pest is quite easily prevented with a soil applied insecticide.
PINE SHOOT BEETLES
This pest is primarily a cosmetic problem, with many drooping, browned out, dead tips hanging. But heavy infestation could be a stressing factor. Soil insecticides can also deal with these beetles.
PITCH MASS BORERS
These borers commonly attack near branch attachments or where branches have been removed by storm or cutting. In small infestations, they are not fatal to the tree, but if plentiful, they can cause a lot of mess down the trunk, dieback of the top, and/or general stress and poor color. That type of stress may pave the way for opportunistic pests to attack. A soil and/or trunk insecticide can be used for this pest, also.
PINE COLLAR WEEVIL
Pine collar weevils can cause decline and death of pine trees. Copy and paste the link below to access an excellent article regarding this destructive pest.