Adulticides like permethrin or deltamethrin are typically applied through ultra-low volume (ULV) fogging in outdoor areas with high biting activity. These treatments don’t eliminate all flying insects, but they sharply reduce the number of active adults for several days. Often used in the evening, when mosquitoes are most active, these products break down quickly in sunlight and don’t leave heavy residues.

For larval stages, specialists usually treat standing water with bacterial agents like *Bacillus thuringiensis israelensis* (Bti). It targets mosquito larvae without harming fish, pets, or beneficial insects. Methoprene, a growth regulator, is another common choice–it interrupts the life cycle before larvae can mature into adults. Some use oil-based products to suffocate larvae at the surface, especially in larger, stagnant bodies like catch basins.

Residual sprays along shady areas, fences, and dense vegetation help discourage resting adults. These products, often microencapsulated pyrethroids, cling to surfaces and offer protection for up to a few weeks, depending on weather. That said, the impact tends to be localized. Rain can wash off treatments early, and mosquitoes can repopulate from neighbouring properties, which is why consistent follow-up is usually part of the plan.

In some neighbourhoods, professionals install CO₂-baited traps or automatic misting systems, but those are less common in Calgary due to climate and cost. Still, in larger yards or near water features, they might be worth considering. None of these options work in isolation–most technicians combine them based on the yard layout, mosquito pressure, and nearby breeding sources.

What Do Pest Control Companies Use for Mosquitoes

Most field technicians rely on a mix of residual insecticides and insect growth regulators to suppress mosquito populations around homes and commercial sites. One of the most widely used active ingredients is bifenthrin–a synthetic pyrethroid known for its long-lasting residual activity on vegetation, fences, and shaded structures. It doesn’t kill instantly, but it holds up well in Calgary’s weather conditions and keeps adult mosquitoes away from treated areas for several weeks.

Larval control is usually handled with bacterial agents like Bacillus thuringiensis israelensis (Bti). It’s applied directly to standing water–ponds, rain barrels, ditches–where larvae develop. Unlike chemical products, Bti targets mosquito larvae specifically without harming fish, pets, or beneficial insects. Some technicians also use methoprene pellets, which don’t kill the larvae outright but prevent them from maturing into biting adults.

Fogging and Misting Treatments

Thermal fogging and ULV (ultra-low volume) misting come into play when the goal is to knock down large numbers of adult mosquitoes fast–say, before an outdoor event or after heavy rains. These applications release fine droplets of permethrin or prallethrin into the air. They’re effective for quick reduction but have little to no residual effect. The next day? You might still see a few flying around, especially if there’s untreated water nearby. So, it’s more of a short-term fix than a long-term solution.

Barrier Sprays and Monthly Programs

For consistent results, barrier spray programs are set up on a recurring schedule, usually every 21 to 30 days during mosquito season. Technicians focus on shaded and humid areas–under decks, around sheds, near compost bins–anywhere these insects like to hide during the day. Most treatments combine contact killers with microencapsulated formulas that release slowly over time. If the property backs onto green space or has drainage issues, these regular applications tend to make the biggest difference.

Types of Insecticides Professionals Apply for Mosquito Control

For outdoor treatments, specialists often go with synthetic pyrethroids–products like deltamethrin or permethrin. These compounds act fast on contact and are typically applied to shaded areas where mosquitoes rest during the day. You’ll often see them used around shrubs, under decks, and along fences. The key is targeting surfaces, not the air.

For fogging or misting, things shift a bit. Pyrethrin-based solutions, derived from chrysanthemum flowers, are still common. They’re biodegradable and break down quickly, which sounds good on paper. But in practice, that means reapplication is usually needed after rain or within a few days. Some techs pair pyrethrins with synergists like piperonyl butoxide to stretch out their impact–though not everyone agrees it makes enough of a difference to justify the extra cost.

Larvicides–mainly methoprene granules or Bti (Bacillus thuringiensis israelensis)–are the go-to for standing water. These don’t kill adult insects; instead, they stop larvae from maturing. It’s a quieter tactic, slower to show results, but it’s the only way to disrupt the breeding cycle long-term.

Professionals also avoid broad-spectrum chemicals that might harm pollinators or aquatic life. That’s something clients don’t always think to ask about, but it’s a reasonable concern–especially if you’re dealing with runoff into drainage or ponds. Some companies even offer organic or low-impact options, but the knock against those is the shorter protection window. Personal experience? I’ve tried both. The synthetic ones work faster and last longer. But there’s a trade-off, especially if you’re worried about exposure near kids or pets.

Curious about how this approach compares to treating other infestations? This page on can pest control get rid of ants breaks it down pretty well.

How Mosquito Fogging Works and When It Is Used

Fogging is typically recommended in outdoor areas with dense vegetation, stagnant water nearby, or after a noticeable spike in biting activity. It’s not an everyday fix–it’s more of a targeted response when larval treatments and habitat reduction haven’t been enough.

The process involves dispersing ultra-low volume (ULV) droplets of insecticide through the air using a fogging machine. The mist floats in the air briefly and contacts adult flying insects directly. Timing matters. Most technicians schedule fogging early in the morning or just before sunset when mosquito activity peaks and the air is calmer, so the droplets hang longer instead of blowing away.

Products used in fogging typically include pyrethroids, like permethrin or deltamethrin, often mixed with a synergist to increase knockdown. These are synthetic versions of naturally occurring compounds found in chrysanthemum flowers. They break down quickly in sunlight and don’t leave much residue, which is helpful in residential areas but also means repeat applications may be necessary after rain or strong wind.

Still, fogging doesn’t reach hidden resting spots under decks, thick shrubs, or tall grass. That’s why it’s often combined with residual barrier treatments or larvicide applications in standing water.

When Fogging Might Be Skipped

• In cooler months or dry conditions where mosquito activity is already low
• If the property has already been treated with a long-lasting barrier spray
• Near water bodies where strict environmental regulations limit airborne products

Some homeowners expect fogging to eliminate every last insect, but that’s not realistic. It’s a control measure, not a cure. For broader outdoor treatment plans that include insects like ants, this article might help: can pest control get rid of ants.

What Larvicides Pest Control Technicians Use to Treat Breeding Sites

To break the mosquito cycle early, most field technicians apply larvicides directly into stagnant water where larvae thrive–gutters, birdbaths, ponds, even puddles that don’t drain well. One of the most widely used solutions is Bacillus thuringiensis israelensis (Bti). It’s a naturally occurring bacterium that targets mosquito larvae without harming fish, pets, or humans. It’s often available in briquette or granular form and stays active for a few weeks.

Another common pick is methoprene, a juvenile hormone mimic. Rather than killing larvae outright, it disrupts their development, so they never mature into biting adults. Some techs prefer this in catch basins or storm drains, especially when longer residual control is needed. Depending on the formulation, methoprene can remain active for up to a month.

Spinosad is a newer option some teams are starting to lean toward, particularly in more regulated environments. It’s derived from soil bacteria and works both by ingestion and contact. It’s not as long-lasting as methoprene but acts fast and doesn’t carry the same resistance concerns.

All of these are meant to supplement–not replace–adult mosquito treatments. If you’re already dealing with flying adults, targeting the breeding sites alone won’t be enough. Timing and coverage matter more than product type, though the right choice can make repeat visits less frequent.

On a side note, if you’re wondering how much is pest control for ants, or curious about how long after pest control can I clean, we’ve broken those questions down separately.

Q&A:

What types of chemicals do pest control companies typically use to eliminate mosquitoes?

Pest control companies apply a variety of chemicals designed to target mosquitoes at different stages of their life cycle. Commonly, they use larvicides that kill mosquito larvae in water sources before they mature, and adulticides that reduce the adult mosquito population. Larvicides often contain bacterial agents like Bacillus thuringiensis israelensis (Bti), which specifically targets mosquito larvae without harming other wildlife. Adulticides usually include synthetic pyrethroids, which act quickly to knock down adult mosquitoes in outdoor areas.

How do pest control professionals decide whether to focus on larvicides or adulticides?

Decisions depend on the mosquito breeding environment and infestation level. Larvicides are applied when standing water with larvae is identified, such as in ponds, gutters, or containers. Treating larvae prevents new mosquitoes from developing, cutting population growth at the source. Adulticides are sprayed when there is an immediate need to reduce the biting adult mosquitoes, often during peak activity times or when complaints have increased. Many pest control plans combine both methods to maximize impact by disrupting the mosquito life cycle at multiple points.

Are the mosquito control treatments used by pest companies safe for pets and beneficial insects?

Most modern mosquito control products are formulated to minimize risks to pets and non-target species. Larvicides like Bti are highly specific to mosquito larvae and do not affect mammals or beneficial insects. Adulticides, particularly pyrethroids, break down quickly in the environment but can be toxic if pets come into direct contact with treated areas immediately after application. Pest control technicians typically follow strict guidelines to apply treatments when pets are indoors or removed, and they advise waiting periods before allowing pets back outside to reduce exposure.

How often do pest control services treat properties for mosquitoes, and what factors influence this schedule?

Frequency varies based on climate, mosquito species present, and property conditions. In regions with warm, wet climates, treatments may be scheduled every two to four weeks during mosquito season to maintain control. Factors like standing water availability, vegetation density, and local mosquito population trends influence the timing. Some companies offer one-time treatments targeting larval habitats, while others provide ongoing maintenance plans with recurring applications to keep mosquito numbers low throughout the season.