Bay County Building
515 Center Avenue
Bay City, Michigan 48708-5941

Spring Aerial Mosquito Treatment to Begin the Week of April 15, 2019

Press Release - For Immediate Release
Contact: Bay County Mosquito Control, Rebecca J. Brandt or Mary J. McCarry
Phone: (989) 894-4555 


As part of a public health initiative to provide for the protection and well-being of Bay County residents, Bay County Mosquito Control (BCMC) will begin conducting its 2019 Aerial Larviciding Treatment the week of April 15, concentrating efforts on seasonally flooded woodlots throughout Bay County. Over a period of 7-10 days, Bay County residents may notice low-flying, yellow or white fixed-wing aircraft over wooded areas between 6:30 a.m. to 8:00 p.m., weather permitting. Controlling mosquito larvae is a critical step in Bay County's comprehensive mosquito control program. To prevent the emergence of biting adult mosquitoes, over 50,000 acres of flooded woodlots will be treated with Bacillus thuringiensis israelensis (Bti), targeting larval stage mosquitoes hatched in the standing water.

Mosquito Control Manager Rebecca Brandt notes that “Bti is a naturally-occurring public health product containing a soil bacterium that specifically affects mosquito larvae, blackflies, and fungus gnats. It has low impact to non-target organisms such as humans, pets, birds, fish, or other aquatic organisms.” The bacterium is attached to a corn cob granule and applied at 3 pounds per acre.

The aerial treatment program has been going on for over thirty years in Bay County. Timing of the aerial treatment campaign is extremely important, weather dependent, and is based on larval development in the woods. Therefore, careful surveillance of the mosquito population before treatment is extremely important. BCMC Biologist Mary McCarry states, “Monitoring weather and mosquito larval populations from initial hatch is necessary in order to time the treatment correctly and promote effective mosquito control.” The larvae must ingest the bacterium to be effective which is why it is crucial to time aerial treatment to the stage when mosquito larvae feed most heartily.

From spring through fall, residents should protect themselves from mosquito bites by applying insect repellent before going outside when mosquitoes are active to reduce the threat of West Nile virus and other emerging mosquito-borne diseases.

To further reduce mosquito habitats in Bay County, Mosquito Control will be holding two scrap tire collections this summer. Scrap tires pose a health concern since they often hold water and are an ideal breeding site for both nuisance and disease-carrying mosquitoes. Bay County Mosquito Control was recently awarded an $8,000 Scrap Tire Clean-Up Grant by the Michigan Department of Environmental Quality to fund these collections. Tire collections for Bay County will take place 9 a.m. - 2 p.m., Saturday, June 1 at Bay County Mosquito Control, and Saturday, August 3 at Fraser Township Hall, 1474 N. Mackinaw Rd., Linwood. Up to 10 passenger car-sized tires without rims will be accepted per household.

Bay County Mosquito Control is a division of the Bay County Environmental Affairs and Community Development department. Manager Rebecca Brandt can be reached at (989) 894-4555 for more information about the aerial larviciding program.