Plan now for spring treatment of hemlock
LANSING — If hemlock trees on your property show signs of hemlock woolly adelgid infestation, now is a good time to plan for spring treatment of this invasive species. Hemlock woolly adelgid native to Asia, has been detected in Allegan, Ottawa, Muskegon Oceana, Mason and Benzie counties in Michigan. These small insects suck sap from hemlock twigs and ultimately can cause tree death.
Insecticides are available to control the insect, and in many cases, landowners easily can apply them by carefully following label instructions and application rate guidance. Due to certain restrictions on the use of these insecticides, you may need the services of a licensed pesticide application business.
If one or more trees are infested, make plans to act this year. Without treatment, trees with hemlock woolly adelgid are likely to die within four to 10 years. Weakened trees on a home landscape could spell disaster during high winds or storms, and eventually they will have to be removed. Loss of hemlocks in forested areas can reduce shade, winter cover, food and habitat for birds, fish and mammals.
Products containing either imidacloprid or dinotefuran as the active ingredient and labeled for use on adelgids are effective in combatting the insect.
No matter which treatment you select, be sure your treatment plan will include all hemlocks on your property over the next few years. If hemlock woolly adelgid is on your site, hemlocks without symptoms are very likely to be infested over time. This includes trees on your property as well as neighboring properties. It s a good idea to discuss treatment plans with neighbors and coordinate efforts when possible.
Can I treat trees myself?
Application of imidacloprid or dinotefuran is simple enough for many landowners to do themselves. Products containing these chemicals are available at garden supply stores, packaged under various trade names in liquid or granular form. Check the label or ask for assistance in selecting the right product.
Imidacloprid and dinotefuran products available at garden supply stores generally are applied to the soil close to the tree trunk, where they are absorbed through the root system. Plan your application for a time between early April and late October when the ground has thawed and soil moisture is moderate — not too dry or saturated. Follow all label directions, wear appropriate safety gear and determine the right application rate to ensure positive results. To protect the environment, do not allow pesticide to enter or runoff into storm drains, drainage ditches, gutters or surface waters.