What chemicals do mosquito spray trucks use?

This is one of the most commonly asked questions whenever somebody hears that a mosquito spraying will be happening around your neighborhood. And since lately these sprayings are becoming a common thing, with all the Zika, West Nile and Dengue fever threats floating around, I thought it would be very beneficial for us to figure out what exactly the mosquito spray trucks are spraying and how it can affect us and our lives.

Usually, both larvacides and pesticides are used when a mosquito spraying is happening in any area. This strategy is employed in order not only to get rid of all the adult mosquitoes in the area, so 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 more mosquitoes maturing and causing us problems. And the sprayings are held during the night, as that is not only the time when the least amount of people and beneficial insects are on the streets but also the time when the mosquitoes are the most active therefore the most mosquitoes can be targeted. But what kind of chemical is actually used by the mosquito trucks?

One of the most commonly used chemical sprays in the so-called ground foggings or foggings that are done from a car or on foot is called Zenivex. It is an effective pesticide, that targets adult mosquitoes, which is why 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 over agricultural crops. The main active ingredient in Zanivex is Etofenprox, which is a so-called adulticide or an insecticide solution that targets adult insects disturbing their nervous system when they come in contact with this chemical, causing eventual death. Luckily for us, the Etofenprox insecticide and therefore by default also Zanivex insecticide has low toxicity to birds and when the spray has dried, it becomes harmless to living creatures like bees and dogs, too. Then also often these mosquito spraying programs use permethrin based solutions, which is another insecticide that is a long-lasting and efficient insecticide, but that, once dry, doesn’t kill beneficial insects like bees and doesn’t harm humans and pets.


All of these solutions, no matter if we are talking about a permethrin-based one, the Zenivex one or a whole different insecticide, are distributed with the help of an ULV fogger or Ultra Low Volume fogger which is able to turn the liquid solution into a very fine fog, providing that the insecticide solution gets into all the small cracks where mosquitoes tend to hide.

Of course, the insecticide still is a chemical, so if you want to be completely sure that you are not breathing it in or that your pets or other things don’t suffer, then I would suggest you close your windows and doors when the spraying is scheduled. As well as to keep you pets indoors and cover you beehives and fish ponds, so they don’t come in contact with the raw, just sprayed insecticide. But really people shouldn’t be that concerned about mosquito spraying, because not only the insecticides that are used are approved by institutions such as Environmental Protection Agency, but also the volume of how much the insecticide is actually sprayed is very small, making up about 10 times weaker of a chemical exposure, than you would experience if you would use a flea shampoo on your dog. And of course, the mosquito spraying is much less harmful than what a mosquito will do to you if it bites you and infects you with one of the mosquito-borne diseases it might carry. So no matter the worries of some, that these sprayings are extremely harmful, the truth is that they affect our lives only positively.

Main website editor at InsectCop.net. Expert in mosquito foggers!


  1. My brother & I used to walk behind the mosquito trucks in the 70’s whenever they sprayed. We are. Oth in poor health. I was wondering if this was related to the chemicals in the fog that they sprayed. We thought it was fun to walk into it & did it way to many times. Are we paying the consequences now? I’m 61 & my brother is 58.

    1. It depends on what was used to kill the mosquitoes. If malathion or an organophosphate were used, which at that time were the more popular mosquito fogging chemical options, then running behind the mosquito truck as a kid shouldn’t be the cause for your poor health. Many think that DDT (which was banned in 1972 but actually isn’t even toxic to humans) was used as the fogging chemical and because of that associate mosquito trucks with poor health. But since DDT is a larvacide it wasn’t used in the fogging trucks, it was mainly put into the water to control mosquito larvae.

  2. was just at a party where we ‘kids’ realized nearly ALL of the moms on the main mosquito truck route (1960s) have had breast cancer. kinda wishing someone would do a map/correlation. we’re assuming the new stuff is safe, of course… then again, our folks were told it was safe back then. (?)

    just as important (maybe, more) is the new standing water in our village — the result of inappropriate building (marshes and low level ponds where there’s used to be grass, stagnant puddles where there used to be a flowing creek). in the last few weeks, they’ve dug trenches that don’t drain to culverts. with our heavy clay soil, these puddles simply aren’t draining (or even evaporating in 98 degree full sun).

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