November 10, 2021 Baltimore County

The Baltimore County Department of Environmental Protection and Sustainability (EPS) is preparing to treat a small, targeted area of Back River next week as proof of concept that helicopter application is a feasible option for controlling nuisance midge populations.

The department expects to spray a naturally-occurring bacterial larvacide from a low-flying helicopter during daylight hours on or about Tuesday, November 16. EPS will monitor the area for midge larvae abundance prior to and after treatment with Bti.
EPS will treat a 50-acre open water area of Back River just southeast of the Eastern Boulevard bridge. A helicopter (black colored Bell, Model 206 L-3, tail number N651HA) will apply a Bacillus thuringiensis israelensis (Bti)-based larvacide. Bti is a naturally occurring bacteria that is found in soil, and is only harmful to certain organisms, specifically midge, black fly and mosquito larvae and a few other aquatic flies. It does not harm people, fish, crabs or other aquatic invertebrates.

More information about Bti is available on the Maryland Department of Agriculture website.
Midges are small non-biting aquatic flies that often swarm near water or marshy areas where they breed, creating a nuisance for homeowners, boaters, businesses and recreational activities. EPS is researching the midge issue in the County’s eastern waterfront areas.
More information about potential plans and funding for future midge mitigation efforts will be released as they become available, pending a successful test application. The test treatment will take place pending County Council approval of an agreement with the vendor