Bacillus thuringiensis israelensis (Bti)

What is it and how does it work?

Bti is a subspecies of Bacillus thuringiensis. Its bacterial proteins affect susceptible larvae after ingestion. Different Bt strains target different insect groups. EPA: Bti for mosquito control explains the underlying ingredient or an example product. An active ingredient is only one part of the finished formulation.

What forms and pests are covered?

Example product forms include granules, briquette / pellet, liquid, spray. Example target groups include mosquito larvae, fungus gnat larvae, black fly larvae. These are drawn from different labels and references, not a claim that every product treats every listed pest. Check the label for the exact species, life stage and use site.

How is it used in pest management?

EPA describes use in labeled water habitats where mosquito larvae develop. Homeowner products include suitable granules or briquettes; commercial liquid formulations have their own directions.

Identify the pest, correct food or moisture problems, close entry points where appropriate, and monitor the result. See our integrated pest management guide. A recurring infestation calls for reassessment, not an automatic stronger dose.

What cautions matter?

Follow the specific water-use label. EPA notes that only certain products are permitted for particular drinking-water settings, and some commercial formulations require dust or mist protection.

Prevent children and pets from contacting stored or applied products. Follow the exact label for protective equipment, ventilation, return intervals, storage and disposal. Do not transfer a pesticide into a drink or food container. Read the label safety guide before selecting a product.

What are its limits?

Bti does not kill adult mosquitoes already flying around a yard. Dump and drain removable standing water first; do not assume a caterpillar-targeting Bt product works on mosquitoes.

The same ingredient in a garden, structural, aquatic or pet product does not make those products interchangeable. This page does not verify current Texas registration, recommend a brand or provide dilution rates, placement quantities or a treatment prescription. Manufacturer sources describe example products, not every formulation.

Where should you check before using a product?

Use the label attached to the exact product you intend to use. Confirm its target pest, permitted site and application method. Check any professional-use restrictions and applicable Texas rules. NPIC explains how to read a pesticide label. Older fact sheets remain useful background, but the current product label takes priority.

For suspected human exposure, follow the label's first-aid instructions and contact Poison Control at 800-222-1222. Call 911 for severe symptoms. For suspected pet exposure, contact a veterinarian immediately.

This field guide is educational and does not offer treatment bookings.