Spray Info & Maps

Gypsy Moth Suppression Program

Gladwin County

Spray Info. & Maps

Text Box: Gladwin County has more than 55,000 acres that could qualify for inclusion in a spray program. In a process we call “fall counts” those acres are surveyed yearly to find the proposed spray blocks for spring. Some blocks are small and require only two stops; some blocks are larger and require more stops. The number of counts that are needed are based upon the number of acres. Acres are then treated by an aerial application of Bt. Bt – Is a native bacterium that is found in nature on plants and in the soil. The strain that we use is Bacillus thuringiensis var. kurstaki(Btk). It only affects leaf eating caterpillars. The timing for the application of the spray is crucial. The caterpillars must be big enough so they are actively feeding yet small enough for the spray to be effective. Such crucial timing makes the application almost specific to gypsy moth. Bt is NOT a contact killer; the caterpillars must ingest the Bt. After eating the leaves with Bt on them, the caterpillars’ digestive system turns the Bt crystals toxic. They develop a belly ache, stop feeding and usually die within 2-3 days. To view a map of the current years acreage click here. Maps are also available at township halls or the program office. Click here to view a chart of the acreage treated in Gladwin County since 1999.

Text Box: Websites that may be of interest: Michigan Gypsy Moth and Exotic Forest Pests Gypsy Moth in North America Michigan Department of Agriculture (MDA) - PPPM Forest Pests of North America Emerald Ash Borer Bugwood Network Michigan Forest Health Highlights (document)