City of Jacksonville


Ultra Low Volume Adulticiding

Past Methods of Adulticiding

Beach Application of DDT, featuring children running to envelop themselves in the fogIn the past, mosquito control districs used large volumes of DDT, those who grew up in the 1950s and 1960s might remember the trucks and the fog trailing behind them.  Some might even remember chasing that fog.  Not only is chasing that fog not recommended, we don't do that anymore.  

Back in those days, little concern was paid to environmental quality, and the potential health ramifications of these methods were unknown. Insecticides were mixed with kerosene or deisel fuel as a carrier, and then heated to produce the characteristic fog.  As a result, several gallons per minute were applied in large swaths.

Using these methods, we managed to eradicate Malaria from the continental united states.  However, between the long-term toxicity of DDT and the application methods, we nearly drove the Perigrine Falcon and other birds of prey to extinction.  This prompted Rachel Carson to write a book called Silent Spring.  It served as a wakeup call to everyone that we needed to do better.

Current Methods of Adulticing

A modern fog truck, utilizing ULV methods to deliver pyrethroidsOur current methods are much better.  We don't use DDT anymore, to start with.  All of the insecticides we use in mosquito control  have very short residence times in the environment because they break down rapidly when exposed to air and light.  Unlike DDT they also break down very rapidly in an animal's body so that they don't accumulate, or magnify up the food chain.  

We utilize a high-pressure nozzel to dispense volumes of only three to four ounces a minute in an invisible (once dispersed) fog with droplet sizes of only a few microns (a thousanth of a millimeter, much smaller than the width of a human hair).  These small particles drift in the air and intercept mosquitoes in flight, but the amount they're actually exposed to is low enough that only small insects like mosquitoes receive a lethal dose.  Animals such as birds, bats, frogs, and pets are not adversely affected. We also spray at night to reduce exposure to beneficial insects such as bees and dragonflies, which are active during the day.  Additionally, because these products are ready-to-use and don't need to be diluted, there is also less chemical residue after the active ingredient has broken down.