Michigan Cooperative
Gypsy Moth Suppression Program

The Michigan Cooperative Gypsy Moth Suppression Program is a voluntary program where federal dollars reimburse county cost for conducting the program at the local level.

Suppression program objectives include protection of tree foliage in wooded residential and recreational areas, reducing caterpillar numbers to tolerable levels, reducing annoyance to people, and providing a control option that limits the use of more toxic application choices.

Up to half the cost of conducting the program is cost-shared by the Michigan Department of Agriculture (MDA) using federal dollars. Typically, the county will provide the remaining half of the administrative costs, while the townships provide the remaining half of the application fees. Some townships are able to take this funding out of their general funds. Other townships may pass a millage, a special assessment, or may bill the private landowners for half the cost of the spray.

The insecticide used in the aerial application is Bacillus thuringiensis, var. kurstaki, or Btk. It is a naturally occurring bacterium that specifically kills caterpillars that are feeding on leaves at the time of application. The Environmental Protection Agency has deemed that Btk is not considered toxic to birds or mammals and does not harm plants. After more than 20 years of testing and studies, Btk is not considered a threat to human health.

MDA has certain guidelines that must be met before a spray block will qualify for cost-sharing. There must be more than one dwelling within 1/10th of a mile in rural areas and at least one dwelling per acre in urban areas. The susceptible forest (wooded area) must have host trees that are 25 feet high or more. Trees must cover at least 50% of the ground when viewed from above for rural areas and at least 25% for urban areas. A minimum infestation level of 300 gypsy moth egg masses per forested acre must be counted in healthy populations.

Currently, Benzie County's Gypsy Moth population is too low to warrant the cost of suppression efforts. This is actually great news! Egg mass counts are still conducted from time to time in order to monitor their numbers. If you think your area is experiencing in increase in the population of the Gypsy Moth, please contact us at (231) 882-4391.

Grand Traverse County has an active suppression program that has been quite successful. A resourceful Gypsy Moth Suppression Program website with informative links has been developed by the Grand Traverse Conservation District. For more detailed information about the life cycle and history of the Gypsy Moth, click here.