Fyfanon insecticide is one of the least toxic insecticides labeled for mosquito control. The mist of insecticide from the sprayer is effective for killing adult mosquitoes approximately 300 feet downwind. Truck spraying is used primarily for localized concentrations of mosquitoes throughout various areas of Miami-Dade County.

When We Spray
Peak mosquito activity is at dusk, with mosquito activity continuing into the evening hours. Mosquito control spray trucks usually begin spraying at dusk to coincide with this peak activity, and continue spraying until all complaints have been serviced. Mosquito spraying is not performed those evening when there are unfavorable climatic conditions such as high winds, rain, or cold temperatures. Spraying under these conditions kills very few mosquitoes.
Spray trucks usually operate five evenings per week, Monday through Friday. Spray operations are extended in instances of severe mosquito annoyance, or when mosquito transmitted disease occur. Control of adult mosquitoes using truck- mounted equipment is not 100% effective, as the spray droplets are not uniformly distributed throughout the area, and the droplets provide control for approximately 300 feet downwind.
 

When We Don't Spray
Spraying is not performed during the day for several reasons:

Mosquitoes are not as active during the day as in the evening, and mosquitoes must be actively flying to obtain effective control.
Beneficial insects, especially honeybees, are active during the daylight hours, and insecticides sprayed can kill them.
People are out during the day, and spraying may cause unneeded exposure to the insecticide. Additionally, traffic congestion would make the operation of a spray truck difficult during business hours.
Thermal currents can cause the insecticide to rise or move in directions not conductive to effective control

Aerial Spraying To Control Adult Mosquitoes
Beech King Air used to spray/kill Bell-47 Helicopter used to spray/kill adult mosquitoes adult and larval mosquitoes

Aerial spray operations are conducted during the summer months using a fixed wing aircraft and a Bell-47 helicopter. The majority of the spraying is performed in the southwest area of the County in response to large numbers of salt marsh mosquitoes that migrate into the area from the Everglades National Park and the Florida Keys.

Aerial spraying is highly effective, but costly. We use the aircraft only to spray large areas that have heavy infestations of mosquitoes.

Aerial spraying is performed at dusk to coincide with the period of greatest mosquito activity. The aircraft most often used is a Beechcraft King Air turbine powered airplane spraying Naled (Dibrom Concentrate) insecticide at the rate of ½ ounce per acre. The aircraft operates at an altitude of 250-300 feet, and sprays at 184 miles per hour.

Spray Notification List
A listing is maintained of individuals who have asked to be notified prior to spray operations. Please contact the Mosquito Control Division if you wish your name to be added to this list. You will be notified by telephone of the date and approximate time of the spray operation.