ULV (Ultra Low Volume)
The other method of control is the ULV (Ultra Low Volume) cold fogging
which places an extremely fine aerosol in the air that floats with the
breeze contacting and controlling the mosquito. This is commonly referred to as
"spraying" or "fogging". The most common method is called ULV (Ultra Low Volume) cold fogging.
We still have this units available on all our truck mounted sprayers. There are some weather conditions that the ULV's still work better (higher wind or inversion conditions) .
Iowa Department of Ag definition of aerosol generators or "fogging machines"
range from small hand held/backpack units to units that fit onto all terrain vehicles
to large truck mounted units. The machines should be pre-calibrated to insure the
correct droplet size and flow rate, thus insuring a correct application.
Mosquito sampling, such as taking a "biting count", is usually done to be sure that
an application is required. The "fogging truck" then drives at 90 degrees to, and upwind of,
the area to be treated, letting the natural air currents assist the application. In large areas,
such as cities or towns, this is typically repeated about every 300 feet. With small hand held type
machines, a swath width of 50 feet is typical.
Because of the extremely small amounts of material used for "fogging", once it has drifted through and area and controlled the mosquitoes, basically there is no residual material left in the area. Repeat applications can made as often as the label allows.