Insecticides For Mosquito Foggers

By: Peter
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insecticides for mosquito foggers

You might have tried a few ways to get rid of mosquitoes but find you are still getting bitten every time you go outside.

Short of covering up, or spraying a repellent on your skin and clothes (which are the most effective forms of protection), you’re at a loss to know what to do. You know it’s important to protect yourself due to the dangerous diseases mosquitoes can spread.

There is a way you can get, at least, a few hours of protection, and that’s mosquito fogging. To implement this method, you will need a mosquito fogger and an insecticide. In this article, we look at the different insecticides that can be used in a mosquito fogger.


Mosquitoes are one of the most annoying insects around. They can wreck a family meal, a camping trip, a fishing expedition, or deprive you of a good night’s sleep with their incessant buzzing around your ears.

The actual bite isn’t that bad. It’s after that it starts itching, and a red bump appears. But the worst thing about mosquitoes is they can transmit dangerous diseases like dengue, chikungunya, West Nile Virus, Zika, and malaria, amongst others.

And it’s not only humans that are affected; horses and dogs can be infected with diseases or parasites.

It’s only the female mosquito that bites. She is looking for a blood meal to provide extra protein to develop her eggs. She is attracted to us by the carbon dioxide we emit. Also, other odors our body puts out from our sweat and skin are attractive.

The first place to start your mosquito control is by removing any standing water on your property and encouraging your neighbors to do the same. Mosquitoes need water to reproduce, and a minimal amount can be enough.

A few places or things you should survey are gutters, old tires, plastic sheets, children’s toys, birdbaths, saucers under pot plants, water butts… – anywhere where water can gather. Any water that can’t be drained should be covered or treated with a larvicide.

Mosquito Fogging

Fogging is a useful weapon in the fight against mosquitos. A mosquito fogger can provide at least a few hours of protection from these pesky insects.

You can carry out the fogging yourself or engage a professional company.

If you use another method of protection, such as traps, you may see fewer skeeters, but they won’t all be eliminated. To be totally protected, you will have to apply a repellent or keep yourself completely covered.

An insect fogger can provide you with much sought-after peace of mind. They are very efficient in destroying adult mosquitoes, but the fogging will have to be repeated whenever you want a few mosquito-free hours.

Fogging only provides temporary relief from mosquitoes, and if used too often or too widely, it could lead to the mosquitoes building up a resistance to the fogging insecticides.

fogging droplet sizes in microns
Droplet sizes

Foggers spray insecticide into the air in the form of mist or fog, with tiny droplets. The droplets stay in the air for a while, and when mosquitoes come into contact with the droplets, they are killed.

Fogging applications are only effective for the length of time the droplets rest airborne. This length of time is dependent on the size of the droplets produced by the fogger; the smaller they are, the longer they are airborne.

There are 2 sorts of foggers – thermal and cold or ULV foggers .

A thermal fogger can either work with electricity or propane. The propane models work with a small gas cylinder and are very portable. With an electric model, you will probably require an extension cable which makes them a little less practical but cheaper to run, as there is no gas cylinder to replace.

They work by heating a coil; then, when the fogging solution passes through the coil, it’s turned into vapor, producing a thick white fog. Thermal foggers aren’t recommended for indoor use.

Cold or ULV foggers are powered by electricity or battery and have a motor that pressurizes the insecticide and forces it out of a special nozzle in the form of a mist. ULV stands for Ultra-low-volume because of the low volume of insecticide needed to create a fog.

Types of Insecticides Used in Mosquito Fogging

Insecticides are chemical or biological agents that control insects. Control may take the form of killing the insect or stopping it from performing destructive activities.

Insecticides can be natural or human-made and are applied in many formulations and delivery systems (fogs, sprays, baits, slow-release diffusion, etc.). In the case of mosquito fogging, you want to kill the mosquito before it can bite you or others.

Residual or Non-Residual

A residual insecticide remains active for a certain time after being applied. The length of time will depend on the formulation of the liquid, the type of surface, and the condition of the surface.

For example, an insecticide applied to mud may be effective for a matter of weeks as the mud will absorb it. The same insecticide applied to something like wood, or a painted surface may be effective for a few months.

Residual insecticides are used with some success in Africa against malaria. Walls are sprayed, and impregnated nets are used on the beds. The problem with using residual insecticides outside is that they can cause greater damage to other insects. Therefore, they are often preferred for use indoors.

A non-residual insecticide works when it is applied and then for a very short time after.

Many fogging insecticides are non-residual; they may also be known as contact insecticides. They must make contact with the insect for it to kill the mosquito. In the case of fogging, the mosquito and the droplet must make contact.

If during fogging a non-residual chemical is applied to tree foliage or other garden plants, it will be effective for a very short time, its effect quickly diminishes. As a result, they will have much less impact on non-target insects.

Water or Oil-Based

Water-based insecticides are ideally suited to ULV fogging. When using a thermal fogger with water-based insecticides, they might be less visible than an oil-based solution. The droplets will be lighter and disperse faster. With increasing environmental concerns about pollution caused by hydrocarbon solvents and possible fire hazards in hot, dry climates, water-based fogging insecticides should be given preference.

Other advantages of water-based insecticides are:

  • more environment friendly
  • almost odorless
  • cheaper than oil-based solutions
  • many come ready for use – less contact with the insecticide for the operator

Oil-based formulations are heavier and will stay in the air for a shorter time. As the droplets will only kill mosquitoes when they are in the air, this is a disadvantage. However, in windy conditions, a heavier fog might be a good thing as it will be less likely to be blown away. However, oil-based insecticides are flammable, they may have an odor, and they can leave stains. For this reason, they are often used outdoors.

Some foggers only accept oil-based solutions, and others only water-based solutions. So before buying an insecticide, check the recommendations from the fogger manufacturer. With luck, your fogger will be able to use both solutions. This will give you a larger range of insecticides to choose from.

Organic or Synthetic

Organic pesticides must be composed of naturally occurring substances. Advertisers often imply that organic products are safer and more environmentally friendly than their synthetic counterparts. This may be true in many cases, but there is no guarantee that natural substances are safer than synthetic insecticides.

Most common organic insecticides are known to be low in toxicity; they break down quickly in nature and are classified as low-impact. However, there are exceptions!

Many people, myself included, prefer using substances found in nature, and it is a good thing we are moving more and more in this direction. However, synthetic insecticides can also be safe and environmentally friendly if used with caution and attention.

Active Ingredients in Fogging Insecticides

A few different active ingredients are used in fogging mosquito control; here are a few of the most common.

Pyrethrins and Pyrethroids

Pyrethrins are insecticides found naturally in chrysanthemums. They have been registered for use in insecticides since the 1950s. Pyrethrins are often considered an organic insecticide when used alone.

However, in fogging solutions, they often have one or two synergists added to make them more effective. Pyrethrins break down rapidly in nature.

Some insecticides containing pyrethrins are ExciteR, and Riptide Waterbased Pyrethrin ULV.

Many fogging insecticides contain synthetic pyrethroids, which are similar to natural pyrethrins. Pyrethroids mimic the effect of pyrethrins. They are modified to be more stable in the natural environment. Some of the most common synthetic pyrethroids you find in fogging insecticides are permethrin, deltamethrin, and d-phenothrin.

Pyrethroids often have a synergist added to make them more effective at killing insects. In fogging solutions, this is often Piperonyl butoxide. These pyrethroid insecticides break down quite rapidly after fogging.

Pyrethrin and pyrethroids work by attacking the mosquitoes’ nervous system and are the most common active ingredients found in fogging insecticides.

Some fogging insecticides containing pyrethroids as the active ingredient are Bonide Mosquito Beater, Black Flag Fogging Insecticide, Repel Fogging Insecticide.


Malathion is a chemical in the organophosphates family and has been registered for use in the US since 1956. Products containing malathion are used outdoors to fight a wide range of insects, including mosquitoes. Malathion kills insects by attacking their nervous system, which stops them from moving or breathing.

Malathion is applied at very low concentrations to control mosquitoes. It is unlikely that most people will experience any adverse effects but always follow the label’s instructions.

Organic Insecticides

Some organic ingredients used in fogging insecticides are:

Spinosad is a natural product made from the fermentation of soil bacteria. It has been registered for use in pesticides since 1997. It works by attacking the insects’ nervous system and is used in Monterey Garden Insect Spray.

Botanical oils such as thyme oil, phenyl ethyl propionate (found in peanuts), and rosemary oil can be found in the EcoVia emulsifiable concentrate.

Wondercide Natural Flea and Tick Yard Garden Spray uses cedarwood oil, sesame oil (from sesame seeds), sodium lauryl sulfate (from coconut.

The insecticides with the active ingredients mentioned above can be ready for use, or it may be necessary to mix with water or oil.

Are the Insecticides Safe for Humans and Animals?

The insecticides used in mosquito fogging are considered relatively safe to humans when applied according to label instructions. Fogging uses very low doses of pesticides and is dispersed in quantities to kill something as small as a mosquito.

Additionally, most pesticides employed are rapidly degraded, and it is unlikely that exposure will occur the day following spraying. Exposure to pesticides may occur if people are outdoors in an area while spraying is occurring.

Better to be cautious and stay indoors during fogging, and if you have breathing problems you could even turn off the air conditioning. Also, best to make sure your pets are indoors during and for a short time after fogging.

Many of these insecticides are toxic to bees, and other insects. Fish and other aquatic insects can also be affected negatively. Long-term exposure can affect their reproduction, with fewer eggs hatching.

If you’re concerned about the effect of the fogging insecticide on the environment you could try a homemade yard repellent. It won’t kill the mosquitoes but may keep them at distance for a few hours.


You may be worried about applying fogging insecticides when considering the risks of using them for non-target or beneficial insects. But mosquitoes and other insects are vectors for numerous diseases, some of which can be fatal, incapacitate you for weeks, or cause birth defects of babies born to mothers infected with the Zika virus. Without fogging and other control methods, there is a good chance that human disease will result. So fogging might be necessary!

Here are a few considerations when choosing a fogging insecticide.

  • It must be compatible with your fogger.
  • Residual or non-residual. Favor non-residual outside to protect non-target species.
  • Oil or water-based. For environmental concerns, use water-based products where possible.
  • Organic or synthetic. Both can be great products. Favor products that degrade quickly to cause the least possible damage to the environment and are effective.
  • Some insecticides come ready to use; this reduces the operator’s exposure to the product.

Fogging should only be one part of your battle against the mosquito population and is aimed at killing adult mosquitoes. You should still take action to eliminate all possible breeding grounds.

Photo of author


Peter spends most of his time outside in his large garden. He has been fighting mosquitoes for a few years trying different traps and repellents without using agressive chemicals.