Mosquito Control of Iowa uses TUG (Thermal ULV Generator) units (1.5 to 3 micron droplet size) and can stay in the air for longer periods of time. The TUG units have became the primary ground fogging equipment that we use in the cities. . We have determined that we achieve much better results then the ULV's. We have the TUG units mounted on all our trucks and ATVs
The other method of control is the 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 & 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.