Baltimore County Executive Johnny Olszewski announces permanent aerial spraying program to reduce midge population at a press conference in Essex. Photo via Facebook Live.

Baltimore County is partnering with the Maryland Department of Agriculture to tackle Back River’s midge swarms, County Executive Johnny Olszewski announced Monday.

Midges – tiny, non-biting flies that often swarm near water or marshy areas – have been a “relentless and fast-growing nuisance,” Olszewski said at a news conference in Essex. 

“Midges have been swarming neighborhoods around Back River for years,” he said, “threatening backyard barbecues, waterfront brunches, and boating trips.” 

Last year, the county ran a pilot program that involved spraying parts of the river with larvicide. The county will now institute a permanent aerial spraying program based on the success of last year’s pilot. 

Throughout spring and summer, the county’s Department of Environmental Protection and Sustainability will spray a 1200-acre section of upper Back River with the non-toxic treatment roughly five to six times. 

The treatment is formulated with a naturally occurring bacteria called Bacillus thuringiensis israelensis (Bti), which is only harmful to midges, flies, and mosquito larvae. 

“This will have absolutely no impact on water, human health, or fish,” Olszewski added. 

“Together, we will bring down this nuisance midge problem, help our residents better enjoy their backyards, and support our amazing local establishments,” he said.