Keep Midge and Filter Flies Under Control with Strike Products

Primarily used in wastewater treatment facilities, Strike products can also be applied in any facility that uses water as part of its process. Midge and filter flies can invade your location if your facility has a water reuse system such as lagoon, lake, pond, or retaining basin. Strike products are the perfect, low-maintenance solution to help keep midge and filter flies under control.

Midge vs. Filter Flies

Midge Fly
Midge Fly
Midge flies alter water quality, clog pipes, and in extreme cases, transmit pathogens. Adult midge flies resemble mosquitoes in appearance with “bushy” antennae, and are ready to mate and lay eggs within days of emergence.
Midge Fly
Filter Fly
Operations also need filter fly control they can count on to combat both the nuisance factor and the potential health risks. Adult filter flies are known for their “hairy” appearance and pointed moth-like wings.
Strike Midge Control

Strike® Midge Control

This microencapsulated liquid formulation is capable of controlling midges and filter flies throughout a facility.

Best for:

  • EPA-approved for use in any natural body of water
  • Continuous applications
  • Enclosed systems
Strike, 1 Gallon11247

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Strike Ultra Professional Midge Control

Strike® Ultra Professional Midge Control

This water-dilutable emulsifiable concentrate is ideal for treating trickle filters and smaller areas where midges and filter flies are a problem.

Best for:

  • Trickle filters
  • Small areas
  • Concentrated fly breeding areas
Strike Ultra, 1 Liter11248

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Strike Pellets

Strike® Pellets

Strike Pellets offer convenient, 30-day release of the EPA-approved insect growth regulator, (S)-methoprene. Formulated for extended holdings times, Strike Pellets are ideal for aerial and ground applications to uniformly and completely treat an area.

Strike Pellets are available in a 22-lb package. As with all Strike formulations, continued use prevents future infestations of midge and filter flies.

Best for:

  • EPA-approved for use in any natural body of water
  • Lagoons
  • Ponds
Strike Pellets, 22 lbs11250

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Application & Use Sites

Wastewater Treatment
Chemical Processing
Pulp & Paper Processing
Food Processing
Golf Courses & Resorts
Wastewater Treatment

Midge and filter flies are more than a nuisance to the staff and surrounding neighbors of wastewater treatment facilities. In severe wastewater infestations, flies can alter water quality, clog pipes/equipment, transmit pathogens and generate complaints from surrounding properties.

Controlling these pests is essential to keeping a wastewater treatment facility operating efficiently.

By targeting the pests during development, urban and rural water management facilities can rely on Strike products to achieve effective midge fly management that breaks the pest life cycle and prevents adult populations from emerging.

Chemical Processing

Midge fly infestations are a big threat to any facility that uses water as part of its process, including chemical processing and pharmaceutical plants.

Midge fly larvae can absorb chemicals in nearby lagoons, emerging as flying contaminated adults. These pests then enter the food chain, impacting the eco-system.

Strike products are the ideal, low-maintenance solution to prevent midge fly breeding in the lagoons used by chemical plants. This not only reduces plant liability, but also keeps plants free of irritating swarms of midge flies that can hinder production.

Pulp & Paper Processing

Water is a key component in paper and pulp mills - and where there is water, there is an opportunity for a midge fly infestation. The Strike product lineup of solutions for midge and filter fly control offers facility maintenance managers, licensed water operators and quality assurance managers convenient, cost-effective formulations.

When these pests enter paper and pulp facilities, they can cause serious quality control issues. Midge flies in a paper plant have been found to contaminate paper rolls and other items manufactured within the mill.

Incorporating Strike products into the mill water systems will keep midge populations under control and reduce the cost of disposing contaminated or tainted paper and the required maintenance. Reducing midge fly populations in the facility and the paper production process is a key factor in paper quality assurance.

Food Processing

Although midge flies are small, they pose a major threat to food processing plants. Food processing plants – especially meat and poultry processors – offer midge flies the food, shelter, and water that they seek.

Not only a nuisance to daily operations, the pests can contaminate the product in the facility, making it inedible and unsafe for human consumption.

With regular applications of Strike products, you can manage the problem at its source and prevent midge flies from contaminating product and compromising health inspections. Plant, maintenance, quality assurance and food safety managers can count on the EPA-approved Strike products to help protect their bottom line and keep operations running smoothly.

Golf Courses & Resorts

High populations of midge flies are aesthetically unappealing, a nuisance for groundskeepers, and most importantly, they can be irritating for residents and guests. Strike products provide easy-to-use midge control for golf course and resort communities, helping to reduce the need for costly repeat applications, limit required maintenance hours, and keep guests and golfers returning for a positive experience.

When applied to golf course lagoons, Strike products simplify the process involved to maintain a scenic golf experience. Treat resort locations with midge fly nuisance issues, including ornamental ponds, lakes, and other non-swimming aquatic areas.

Formulated for extended holding times, Strike Midge Fly Control Pellets are ideal for aerial and ground applications. Continued use prevents future golf course and resort infestations of midge flies.


Strike Products are used primarily in wastewater treatment facilities, but they can be applied in any facility that uses water as part of its process. Midge and filter flies are not exclusive to wastewater facilities. If your facility has a water reuse system, retaining basins, lagoons or even a lake or a pond, midge and filter flies can invade your location.

Don’t see your type of operation listed above? No problem. The environmental compatibility of Strike products make them a great solution for midge and filter flies in many water treatment or aquatic sites.

See the Results

It has been proven that the insect growth regulator (IGR) in Strike® products is highly effective in eliminating midge and filter fly infestations and keeping them under control without the use of harmful ingredients.

Product Brochure

Download our brochure to learn how to improve the performance of your facility by controlling midge and filter flies with Strike® products.


Have any questions? Check out our FAQ to assist you in maximizing your midge and filter fly control efforts on your operation.
Entomologists have done studies on the control of midge and filter flies in wastewater facilities. It has been proven that the insect growth regulator (IGR) in Strike products is highly effective in eliminating infestations and keeping them under control without the use of harmful ingredients.
Strike Midge Control For Filter Flies at Barnesville, GA
By: D. Craig Sheppard Department of Entomology, University of Georgia Coastal Plain Experiment Station Tifton, GA 31793 Reprinted with Permission.
Filter flies, or moth flies, often breed in huge numbers in the gelatinous film covering the trickling filters at wastewater treatment plants. The dense flight of adults can cause nuisance situations at the site and nearby areas. Thermal or ULV aerosol insecticide treatments are recommended for adult control, but repeated treatments are needed for satisfactory control.
The study reported here explores a low-labor (S)-methoprene treatment that prevents adult emergence. In mosquitoes, (S)-methoprene, an insect growth regulator (IGR), prevents metamorphosis into the adult stage. Immature mosquitoes usually die as pupae. This same scenario is assumed for the filter fly.
Materials and Methods
This study was conducted at the municipal wastewater treatment plant in Barnesville, Ga. Adult filter flies were monitored periodically with seven, five by seven inch sticky cards positioned around the upper inside rim of the primary biological oxygen demand (BOD) tower (trickling filter). Sticky cards were usually placed in mid-morning when activity was high and were always left for 15 minutes. Captured flies were counted and recorded. Sampling dates are given in Table 1.
Table 1: Trickling Filter Fly Counts - Barnesville, Ga - 1996 Sticky Cards Exposed 15 Minutes
Trickling Filter Fly Counts
The larvicide treatment was five ounces of Strike (20% (S)-methoprene) diluted in approximately 10 gallons of water and then introduced into the splitter box over 24 hours. The splitter box is positioned just before the primary BOD tower on the wastewater flow. This treatment was started on July 10, 1996 and continued for 29 days through August 7, 1996. Treatment was stopped on August 8, 1996.
Water samples were taken from the top and bottom of the primary BOD tower on August 7, the last full day of treatment. These were frozen and shipped on dry ice to Wellmark International in Dallas, TX for analysis of (S)-methoprene.
Results and Discussion
Adult filter fly counts are given in Table 1 and Figure 1. Sampling began on an increasing population with total counts going from 475 on May 10, 1996 to 1451 on July 17, 1996. At this higher level, they were judged to be abundant and a nuisance by the plant operator.
Figure 1: Filter Fly Counts - Barnesville, GA 1996
Filter Fly Counts
The (S)-methoprene treatment begun on July 10 had a clear effect by July 31, three weeks later. During the first week of treatment, adult numbers continued to increase to 1451, but had decreased to 10 two weeks later. Adult numbers continued to be very low for at least two weeks after treatment was stopped, and increased very slowly to 76 two months later. This was in mid-October, and cool nights were probably beginning to reduce adult emergence.
The 29 day (S)-methoprene treatment was judged to be highly successful, giving control up to 99.7 percent. In mid-October, plant personnel still judged control to be good, over two months after treatment had stopped.
What are midge flies?

Midge flies, or chironomids, are one of the most common species of insects surrounding standing water sites. They are commonly found in wastewater treatment plants and along lake shores, but can tolerate a variety of environments. Chironomid midges lay eggs in slow-moving as well as stagnant water, in quantities of up to 3,000 at a time. After approximately one week, the eggs hatch to form larvae, also called bloodworms. The chironomid larvae thrive in nutrient-rich conditions, such as bacteria and sludge in wastewater treatment plants or other organic matter in lakes and ornamental ponds. Within approximately 10 days, the bloodworms mature into adult flies and start the cycle again. Severe chironomid midge fly infestations should be addressed to avoid nuisance issues and water quality problems.

What is the difference between a chironomid and a gall midge fly?

Gall midge flies, family Cecidomyiidae, differ from chironomid midge flies, as the larvae live in the leaves and flowers of plants. The presence of gall midges causes the plant tissue to swell, forming galls. The family Chironomidae consists of nearly 2,000 species. Chironomid larvae are herbivorous and can be found in water sites.

What are filter flies?

Drain flies, sink flies, moth flies, or sewer gnats (Psychodidae) are small true flies (Diptera) with hairy bodies and wings; one of their common names, moth flies.There are more than 4,700 known species. The adults live for approximately 20 days, during which they will breed only once, often within hours of emerging from their pupal casings. Females will lay their eggs (between 30 and 100) just above the water line inside moist drains. Removing the breeding site is the most important part of a drain fly control program.

What is Strike?

Strike is a highly effective larvicide for the control of nuisance flies at wastewater treatment facilities.

What makes Strike unique?

Strike contains an insect growth regulator (IGR). IGRs are unique in that they do not control pests in the ways that conventional pesticides do. Conventional pesticides kill the adults, whereas IGRs work by controlling the emergence of adult pests from the pupal stage.

How does the IGR in Strike control flies?

IGRs are mimics of natural products in an insect's body. A pest absorbs the IGR into its system, where it disrupts normal development and causes the insect to remain in the pupal stage where it dies. In other words, IGRs prevent flies from becoming the adults that create the nuisance to workers and surrounding residential areas.

How is Strike applied?

Strike is dispensed via a free-standing unit that contains a tank, metering pump, stand and mixing device. All of the equipment runs on 120 volts, and typical setup takes less than 15 minutes.

Where should I apply Strike?

Strike should be applied to infested areas, including lagoons, ponds, and in wastewater treatment facilities where the sewage enters the system after primary treatment (grit and sediment separation). Make applications at the headworks or discharge box as the sewage enters the infested area.

How much Strike liquid needs to be applied?

Strike is applied at the rate of 5 ounces (3 oz for Ultra) per 1 million gallons of flow per day. Meter the correct amount of Strike into the influent side over a 6 to 8 hour period of low flow. Continue the 5-ounce per million gallons rate for 7 to 10 days.

Do Strike liquid products require special handling?

No. They are water-based liquid concentrates which are easy to handle, mix and use. The active ingredient is Strike liquids is active only against insects and is one of the most environmentally compatible insect control products on the market.

Will Strike interfere with microbiological activity in the facility?

No. Because the active ingredient in Strike affects only insects, there is no need for concern about effects on the beneficial microbes. Nor do the inert ingredients in Strike cause a problem.

What areas of a wastewater facility can be treated?

Strike can be used anywhere in the facility where midges and filter flies are a problem. Typical application sites include trickling filters, sludge drying beds, clarifiers and any other location where nuisance flies are breeding.

Will using Strike Products for midge and filter fly treatments raise the level of toxicity in the water?

No. Strike products have a relatively short half-life. After normal filtration and UV treatments, Strike products are typically undetectable when water is tested.

What makes Strike different than other products used for fly control?

Strike is unlike any other product used to control filter flies. Strike attacks the pest problem at the source - the organic matter associated with wastewater facilities. Strike products control the larvae before they become adults, thus breaking the cycle of infestation. By preventing the larvae from becoming adults, there are no adults to continue the cycle. While other products kill only a small portion of adult flies, Strike controls them at the source of the infestation.