Photos by Whit Pennington, Mosquito Control staff hand spraying in pond.
August 16, 2013
By Glen Pourciau
In Leon County there are more than 40 different species of mosquitoes with only about 15 of these species considered to be of economic or medical importance, meaning they are a nuisance that can cause health problems. Leon County provides mosquito control services to city and county residents to support public health and reduce human discomfort associated with large mosquito populations.
The mission of Leon County’s Mosquito Control Program is to provide residents effective and environmentally sound mosquito control services. Mosquito control services include truck sprays, hand sprays, larvicide applications, domestic inspections, mosquitofish introductions, and public education programs. Depending on mosquito census data, best management practices, weather conditions, and legal requirements, trained Mosquito Control staff have the responsibility to determine the timing, method, and areas of treatment. Mosquito control services are done on a request basis with the greatest demands typically occurring during the summer months or following significant rainfall events. For example, during 2012, in response to Tropical Storm Debby, Leon County responded to more than 6,900 mosquito control service requests which were received during the month of July.
When breeding habitats can be identified, the most efficient ways to control mosquitoes is through source reduction, larviciding, or mosquitofish introductions. Source reduction is removing the habitat the mosquitoes breed in such as draining a bucket filled with water. Larviciding is a method of killing the larvae directly with a chemical. For mosquitofish introductions we use a minnow sized native fish called Gambusia. These methods are effective because they target the mosquito larvae before they become a blood-sucking adult. In areas where breeding habitats are not known or are inaccessible, truck sprays provide the most efficient control for the adult mosquitoes biting in the evening while hand sprays provide the best method for treating daytime-biting, adult mosquitoes.
For each type of application, Mosquito Control staff use the most effective, least toxic chemical available. For example, several of the products used during larvicide applications use Bt, a naturally occurring bacteria, to control the larvae. Bt is often used by organic gardeners to control pests. Truck sprays and hand sprays use synthetic pyrethroids to control adult mosquitoes. These products are based on naturally occurring pyrethrins found in Chrysanthemum flowers and breakdown quickly in the environment. Trucks are run during the evening hours when the adult mosquitoes are the most active and when non-target insects (bees, butterflies, dragonflies, etc.) are least active. This timing increases the impact to mosquitoes and reduces impact to non-target species. More information regarding the chemicals used can be found on the Mosquito Control website.
When it is found that water-holding containers are the source of the mosquitoes, as is often the case with the Asian tiger mosquito, education plays a major role in empowering citizens to help reduce mosquito problems. The main focus of education is “Finding Them before They Find You” to help citizens be aware of and minimize potential breeding habitat. Mosquito Control staff conduct presentations to adult groups, organizations, businesses, neighborhood associations, school programs, and individual homeowners. When everyone does their part in eliminating places where mosquitoes breed in their yards and neighborhoods, we can all enjoy our outdoor time more and lessen the incidence of the diseases some mosquitoes carry.
Diseases transmitted by mosquitoes are always of great concern. Mosquito Control staff maintains seven sentinel chicken flocks throughout the county and monitors for Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) activity. In the event of increased viral activity Leon County works with the Health Department to issue necessary advisories and targets control efforts to minimize the potential spread of these diseases.
If you find yourself experiencing problems with mosquitoes or have questions regarding the types of control methods, please contact Leon County Mosquito Control at 850-606-1400 or at the website: www.LeonCountyFL.gov/mosquito. Mosquito control services are available to all city and county residents. Hand-sprays may be done twice per calendar year at no cost with additional hand-sprays costing $25 per treatment, payable at time of service.
Glen Pourciau is the Stormwater Superintendent for Leon County Public Works. For more information about gardening in our area, visit the UF/ IFAS Leon County Extension website at http://leon.ifas.ufl.edu. For gardening questions, email us at Ask-A-Mastergardener@leoncountyfl.gov