This is one of the most commonly asked questions whenever somebody hears that a mosquito spraying will be happening in their neighborhood. Since these sprayings are becoming a more common thing with all the Zika virus, West Nile fever, and dengue fever threats floating around, I thought it would be beneficial for us to find out what exactly the mosquito trucks are spraying and how it can affect us.

What Do the Sprayings Target?

Usually, both larvicides and pesticides are used when a mosquito spraying happens in any area. This strategy is employed not only to get rid of all the adult mosquitoes in the area so that there is less of a chance that you will be bitten by a mosquito but also to get rid of mosquito larvae so there are no mosquitoes waiting to mature and cause more problems. The sprayings take place at night as that is not only the time when the least amount of people and beneficial insects are on the streets but also because it is the time when the mosquitoes are the most active therefore the most mosquitoes can be targeted.

What Chemicals Are Actually Used by the Mosquito Trucks?

One of the chemicals that is most commonly used in the ground foggings or those done from a car or on foot is Zenivex. This is an effective pesticide that targets adult mosquitoes. For that reason, it usually is used in conjunction with a larvicide. It is an oil-based fogging solution that can be used in both urban and rural areas since it is approved for use even on agricultural crops. The main active ingredient in Zenivex is etofenprox, an adulticide, which is an insecticide that targets adult insects by disturbing their nervous system when they come in contact with the chemical, eventually causing death. Luckily, etofenprox insecticides and, therefore, by default also Zenivex, have a low toxicity for birds. When the spray has dried, it becomes harmless to living creatures like bees and dogs as well.

Mosquito spraying programs also use permethrin-based solutions, which is another insecticide that is long-lasting and efficient. Once dry, it does not kill beneficial insects like bees and does not harm humans and pets either.


What Should You Do When a Spraying Is Scheduled?

All of these solutions, whether a permethrin-based one, Zenivex, or an entirely different insecticide are distributed with the help of an ultra-low volume (ULV) fogger which is able to turn the liquid solution into a very fine fog, allowing the insecticide solution to penetrate into all of the small cracks where mosquitoes tend to hide.

Of course, any insecticide is still a chemical, so if you want to be completely sure that you are not breathing it in and that your pets or other things will not suffer, then I would suggest that you close your windows and doors when the spraying is scheduled. You should also keep your pets indoors and cover your beehives and fish ponds so they do not come into contact with the freshly sprayed insecticide.

But, people really shouldn’t be that concerned about mosquito spraying because not only are these insecticides approved by institutions such as the US Environmental Protection Agency but also because the volume of insecticide used is actually very small. In the end, it is a chemical exposure that is about 10 times weaker than you would experience if you used a flea shampoo on your dog. And, of course, the mosquito spray is much less harmful than what a mosquito could do to you if it were to bite you and infect you with a disease. So, even though some may worry that these sprayings are harmful, the truth is that they only affect our lives in a positive way.