The Georgetown County Mosquito Control Division primarily uses two chemicals for Mosquito Control: Permethrin and Naled. According to the Environmental Protection Agency, in the application methods used by our staff, neither product is harmful to humans, pets and birds.
Permethrin is currently used in the county’s Spray Trucks in an Ultra-Low Volume (ULV) application -- in other words, an aerosol which contains very tiny droplets. Studies conducted by various universities and the EPA have shown that large beneficial insects, such as butterflies, are less likely to be harmed by a single ULV application because of their size. The county’s spray trucks typically spray an area once every two to three weeks and, since the Permethrin dissipates within a day, there are no lingering effects.
Naled is used in aerial spraying and, once again, is not harmful to humans, pets, birds and large beneficial insects from a single application, due to the tiny droplet size. It also dissipates within a day, reducing any lingering effects.
These products are highly regulated by the EPA and only used in small concentrations. (For example: only 3/4 of an ounce of Naled is used to spray one acre).
The Mosquito Control staff is highly sensitive to the effects of these chemicals on the environment. Most of the spraying is conducted in the early morning and evening when mosquitoes are active but other insects are not. The staff is dedicated to protecting the environment and are constantly looking for alternative methods of controlling mosquitoes without harming humans, pets, birds and beneficial insects.