Will foggers kill gnats and fruit flies?

Gnats and fruit flies can be frustrating pests that seem to appear out of nowhere in homes. They are attracted to ripe fruit, standing water, and garbage. Many homeowners look to foggers as a quick solution to get rid of an infestation of small flying insects like gnats and fruit flies. Foggers, also known as total release insecticides, work by dispersing a fine mist of insecticide throughout an enclosed space. But are foggers effective against gnats and fruit flies? Here is a look at whether foggers can kill gnats and fruit flies.

What are gnats?

Gnats are very small flying insects that are often drawn to decaying organic material. There are many different species of gnats such as fungus gnats, buffalo gnats, and eye gnats. Two common types of gnats found around homes are:

Fruit flies

Fruit flies are tiny flies that get their name from their attraction to ripened or rotting fruit. They lay their eggs near the surface of fermenting fruits and vegetables in kitchens. They can also breed in drains, garbage disposals, empty bottles and cans that contain traces of fruit juice or soft drinks. The adults grow to about 1/8 inch long and have red eyes and yellow-brown bodies.

Drain flies

Drain flies breed in the slime and organic matter that builds up in drains. The larvae develop in the gelatinous gunk coating pipes. Drain flies are also called filter flies or sewage flies. They are often seen hovering around sink drains. The adults grow to about 1/5 inch long and have fuzzy wings and bodies.

What attracts gnats?

Gnats are drawn to moisture, decaying organic material, and standing water where they can breed. Common gnat attractants include:

• Ripe or rotting fruit
• Vegetables
• Standing water or moist soil
• Drains
• Garbage and compost piles
• Pet food
• Sinks and shower drains

Gnats will congregate anywhere that provides ideal conditions for laying eggs. They only need a very small area of moisture and rotting matter to breed successfully.

Do foggers kill gnats?

Foggers do kill adult gnats through direct contact with the insecticide fog. However, foggers often do not kill gnat eggs and larvae hidden down in drains, soil, and tiny crevices. After fogging, new adult gnats may continue to emerge from breeding areas that were not reached by the insecticide.

Here are some key points on using foggers for gnats:

• Foggers will kill adult gnats flying in the open areas of a room.
• The mist cannot penetrate down into drains and cracks where gnats breed.
• Any gnats in protected areas like under furniture or in other rooms will be unaffected.
• The fogger will not prevent new gnats from emerging.
• You will need to find and eliminate breeding sites to get rid of gnat infestations.

Foggers alone will not fully eliminate an infestation. The insecticide mist only kills the adult life stage and does not stop gnats from continuing to breed.

Tips for using foggers on gnats

Here are some tips to get the most effectiveness from foggers against gnats:

• Carefully follow all label directions – using too much or too little insecticide can make foggers ineffective.
• Make sure to fully seal the room – seal up any vents, chimneys, open doors and windows. The fog needs to fill the space completely.
• Remove pets and houseplants – properly protect or remove any people, animals and plants from the area before fogging.
• Cover exposed food, dishes and surfaces – the insecticide residue can contaminate anything left uncovered.
• Remove gnats from drains – pour boiling water or a drain cleaner down sinks and drains to kill gnats before fogging.
• Consider repeat applications – it may take more than one fogger treatment to kill newly emerged adult gnats.
• Find and eliminate breeding sites – drain flies breed in gunk in drains and pipes which needs to be cleaned out.

Do foggers kill fruit flies?

Foggers are somewhat more effective against fruit flies compared to gnats. The insecticide fog can kill adult fruit flies on contact. However, foggers have limitations when it comes to fruit fly control:

• The fog may not penetrate small spaces where fruit flies breed.
• Any larvae and eggs will be unaffected by the insecticide.
• Foggers do not provide any residual activity to kill newly emerged flies.
• You still need to clean up and discard rotting fruit and vegetables that breed flies.

As with gnats, foggers will only kill the adult stage of fruit flies currently flying in the open. The insecticide has no lasting effect. Foggers do not continue killing fruit flies after the treatment. To get rid of fruit fly infestations, you need to find and eliminate their breeding sources.

Tips for using foggers on fruit flies

Here are some recommendations to maximize fruit fly control when using foggers:

• Remove or cover any fruit – exposed fruit will just continue breeding flies after fogging.
• Clean drains and disposals – remove any organic matter where flies can breed.
• Seal the area completely – fruit flies can escape through the tiniest openings.
• Allow fog to penetrate – give the mist at least a couple hours to fill all areas.
• Take out the trash – discard rotting fruit, vegetables and other waste.
• Use other control methods – foggers work best paired with sanitation and traps.

As with gnats, also follow all label directions and ventilate properly after fogging. Foggers alone will not provide complete or long-term fruit fly control. You need to continue removing breeding sites after treatment.

Are foggers effective for indoor use?

Foggers are labeled for indoor use in confined spaces like closed rooms, basements, attics, garages, and sheds. They are not intended for open outdoor areas. When used properly indoors, foggers can provide control of flying pests like gnats, flies, mosquitoes, moths and fleas.

However, foggers have some drawbacks when used indoors:

• The fine mist can contaminate surfaces, food, dishes and exposed belongings.
• Pet birds and reptiles can be very sensitive to the insecticide residues.
• The chemicals linger and recirculate through HVAC systems.
• People and pets need to be removed from the building during treatment.
• The mist cannot reach into all breeding spaces in walls, under appliances, etc.

Foggers are most effective in confined spaces without furnishings. The insecticide mist cannot penetrate into cracks, crevices and porous materials where insects hide and breed. Foggers work best for adult flying pests exposed in the open.

Are insect growth regulator (IGR) foggers better?

Some foggers contain insect growth regulators (IGRs) in addition to insecticide. IGRs mimic hormones that prevent immature insects from developing into adults. They can help provide longer-lasting control by breaking the breeding cycle.

Here are the advantages of using an IGR fogger:

• IGRs prevent eggs and larvae from reaching adulthood.
• They can provide residual activity up to 7 months.
• IGRs have low toxicity to people and pets.
• They do not require any cleaning up of surfaces after fogging.
• IGRs are effective even in areas missed by the insecticide fog.

The addition of an IGR gives foggers more long-term control by affecting immature life stages. This can help reduce populations over time. However, IGR foggers still will not penetrate to all breeding areas. So you still need to use them alongside proper sanitation and breeding site reduction.

Are foggers safe?

Foggers contain synthetic pyrethroid insecticides like pyrethrins, permethrin, cypermethrin or tetramethrin. When used according to label directions, foggers are generally safe for indoor residential use.

However, some precautions need to be taken when using foggers:

• Always read and follow all label safety directions.
• Remove pets, birds, fish and cover aquariums before fogging.
• Remove or tightly cover any exposed food, dishes, utensils.
• Turn off all ignition sources – foggers are flammable.
• Vacate the treated area and do not reenter for at least 2 hours.
• Open windows and doors when reentering and ventilate for 30 minutes before occupying.
• Wash all exposed surfaces and floors thoroughly after treatment.
• Avoid repeated fogger use and use when pregnant or with respiratory issues.

When label directions are not followed, foggers can cause issues like:

• Asthma or breathing problems when reentering too soon.
• Irritated skin, eyes, throat, nose.
• Contaminated food or belongings.
• Pet or wildlife poisoning.

Use foggers only when necessary, at the recommended frequency, and along with other IPM control methods for best results. Consider lower-risk options first like sanitation, traps, caulking cracks, screening vents, and drain treatment.

What is the proper way to use a fogger?

Here are some tips for safely using foggers in an enclosed area:

1. Carefully read and follow all label directions.
2. Calculate the needed number of foggers based on room size.
3. Turn off all flames, pilot lights and ignition sources.
4. Cover or remove food, dishes, pets, plants.
5. Close windows and interior doors and seal all external doors/openings.
6. Place foggers in corners, on tables or suspend above floor.
7. Activate foggers and immediately vacate sealed area.
8. Keep area sealed for at least 2 hours after activation.
9. Return and air out space for 30 minutes before reoccupying.
10. Wash any exposed surfaces and floors after fog has settled.
11. Properly discard empty canisters.

Always take safety precautions when using total release foggers. Read the label thoroughly prior to use and follow all stated directions. Using too many foggers or activating foggers improperly can lead to health issues or fire hazards.

Conclusion

Foggers can provide temporary reduction of some flying insects like gnats, fruit flies, mosquitoes and moths by killing exposed adult stages. However, they do not provide complete or long-term control. Foggers do not penetrate into all breeding areas to kill eggs and larvae. And they leave no residual activity to kill newly emerged adults.

While foggers can quickly knock down populations of adults, reinfestation will continue without proper sanitation and elimination of breeding sites. Foggers work best when combined with non-chemical methods like sanitation, exclusion, traps, and target treatments of breeding areas. Using IGR foggers and repeating treatments may improve control. But foggers alone will not eliminate an established gnat or fruit fly problem.

To fully get rid of gnats and fruit flies, you need diligent inspection to find and destroy breeding sources. This allows you to target problem areas with boiling water, drain treatment, or removal of waste. Continued cleaning and exclusion also helps deny flies and gnats access to food and breeding areas. When used occasionally alongside non-chemical control methods, foggers can provide a quick knockdown of adult populations. But fogging should not be relied on as the sole or primary method of fly or gnat control.