Midge Fly and Red Worm Control

EPA-registered biological larvicide for midge flies, red worms and bloodworms in wastewater lagoons and treatment plants, dosed by flow or acreage.

Short answer

Midge flies and red worms are controlled biologically with Bacillus thuringiensis larvicide, which breaks the larval stage of the life cycle without harming treatment biology or creating effluent toxicity. Dosing runs twice weekly for four weeks initially, then weekly for maintenance, set by plant flow or lagoon acreage.

What we carry

AQUABACxt

For: midge fly swarms drawing complaints from the neighbourhood

US EPA-registered Bacillus thuringiensis larvicide for red worms and midge flies in wastewater lagoons and plants. Safe for treatment biology.

$335Liquid, 5 gallon case

Midge Fly Complete

For: a red worm infestation that resisted larvicide alone

EPA-registered larvicide paired with an enzyme that breaks down red worm cocoons, exposing more larvae to treatment. Complete midge fly control program.

$630Two-part liquid program

Which one for which problem

Product	Reach for it when	Form	Applied from	Timeline
AQUABACxt	Midge fly swarms drawing complaints from the neighbourhood	Liquid, 5 gallon case	Dosed to the plant or lagoon	Four week initial campaign
Midge Fly Complete	A red worm infestation that resisted larvicide alone	Two-part liquid program	Dosed to the plant or lagoon	Four week initial campaign

Plenty of systems run more than one of these. They are complementary far more often than they are alternatives, and each product page says which it pairs with and why.

Midge flies get treated as a public relations problem, and in a small community they certainly are one. But the larvae, red worms and bloodworms, feed on the biomass doing your treatment, so a heavy infestation is a process problem before anyone complains about a swarm.

Break the life cycle, not the biology

Broad-spectrum insecticides are the wrong tool in a permitted system: they risk effluent toxicity and they hit the biology you depend on. The biological route uses Bacillus thuringiensis, whose endotoxins are specific to target larvae and are US EPA-registered for this use.

Product	Use
AQUABACxt	The larvicide on its own, dosed by plant flow or lagoon acreage
Midge Fly Complete	The larvicide paired with an enzyme treatment as a full program

Dosing is a campaign, not a single application

The pattern that works is an initial period of frequent dosing to break the reproducing population, followed by maintenance dosing to keep it broken. Skipping the maintenance phase because the swarms stopped is the most common way a site finds itself repeating the initial campaign the following season.

Adults already flying are unaffected by a larvicide and have to die off naturally, so judge the treatment by what emerges next rather than by what is in the air today.

Common questions

Why are midge flies a treatment problem and not just a nuisance?

Red worms are midge fly larvae, and they feed on the biomass doing your treatment. Beyond the community complaints that come with a swarm, a heavy infestation consumes mixed liquor solids and disrupts the process. The nuisance is what gets reported; the treatment loss is what costs you.

Will a larvicide harm my treatment biology?

No. Bacillus thuringiensis produces endotoxins specific to the larvae of target insects. It is US EPA-registered, safe for the wider ecosystem, and does not create effluent toxicity problems, which is exactly why it is preferred over broad-spectrum insecticides in a permitted system.

Do the larvae build resistance?

It is difficult for them to, because the product works through six distinct endotoxin compounds rather than a single mode of action. That is the practical advantage over single-mechanism larvicides where resistance develops over successive seasons.

How long before the swarms stop?

The larvicide breaks the life cycle at the larval stage, so adults already flying are unaffected and have to die off naturally. Expect the initial four-week dosing period to show through as fewer emerging adults rather than as an immediate change, then maintenance dosing to hold it.

Read before you buy

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