From Harford County government:
Harford County government will once again participate in the Maryland Dept. of Agriculture’s annual Mosquito Control Program, which begins for the 2016 season on May 23 and will end sometime between September 23 and October 4, depending on the weather. Spraying to control adult mosquitos will take place at the following Harford County Parks & Recreation facilities: Flying Point Park, Mariner Point Park, Lake Serene, Swan Harbor Farm, and at the Equestrian Center for the county farm fair.
For more information about mosquito control program activities and policies, please contact the Maryland Dept. of Agriculture at 301-422-5080 or visit their website http://mda.maryland.gov/plants-pests/Pages/mosquito_control_policy.aspx. The website includes an Adult Mosquito Control Exemption form. To contact the Harford County Department of Parks and Recreation, please call 410-638-4753.