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Mosquito Control in Morris County

Posted: March 10, 2016

The Morris County Division of Mosquito Control, a division of the Morris County Department of Planning & Public Works, has the goal of reducing the number of nuisance and disease transmitting mosquitoes within the county.

The division employs several techniques to provide this service to residents with minimal impact on the environment. Its programs can be summarized as follows:

Water Management
Extensive efforts are made to remove blockages from Morris County waterways and to maintain drainage systems as needed. Work is done carefully, with environmental impacts kept clearly in mind. This helps reduce the use of insecticides needed to control mosquitoes.

Larval Control
Mosquitoes all start out in water as larvae, or “wrigglers.” In areas where water management is not feasible, larval control is necessary. Some locations are suitable for stocking with mosquitofish, which provide continuous, biological control of mosquitoes. In other areas, larvicides may be used to eliminate mosquitoes. Products are chosen that are specific for mosquitoes and have minimal or no effect on other organisms in the aquatic environment for this purpose, and these are applied by trained staff licensed by the New Jersey Department of Environmental Protection (NJDEP). All products are registered with both the United States Environmental Protection Agency (USEPA) and the NJDEP which means they are legal to use in New Jersey and are reviewed and recommended by the New Jersey Agricultural Experiment Station, Cook College/Rutgers University. Locations receive treatment only when surveys show that large numbers of mosquitoes are a threat to populated regions. These products are applied by hand crews, by all terrain vehicles or by helicopter. Larval habitats are treated only when larvae are present.

Adult Control
Although this is the most visible aspect of mosquito control, control of adult mosquitoes is a last resort—division staff try to stop mosquitoes before they are out and flying around.
When adult control is needed because of a severe mosquito infestation, truck mounted sprayers are generally used that apply 1/2 to 1 ounce of material per acre. Sometimes, small hand sprayers are used to treat remote locations.


Homeowners can help control mosquitoes by making sure they do not have containers around the home that hold water. Buckets, gutters, bird baths, toys, tarpaulins and anything else than can contain water should be emptied or removed from the yard. Do not dispose of leaves and grass clippings in ditches, streams or catch basins. Make sure your screens are in good repair, and consider moving inside during periods of high mosquito activity (early evening and early morning).

For more specific information on mosquito spraying in Morris County, call the Morris County Division of Mosquito Control at 973.285.6450 or visit their website.