Silver City Vector Control Task Force

What is Bacillus thuringienses?

Bacillus thuringiensis (Bt) is a naturally occurring, soil borne organism that has gained recent popularity for its ability to control certain insect pests in a natural, environmentally friendly manner.

Bt israeliensis is highly effective against mosquito larvae and black fly larvae. Bti comes in two forms: granular and solid dunks. Both can be used wherever mosquitoes breed: the periphery of ponds, lakes, flooded orchards, ditches, pastures, sewage or animal waste lagoons, roof gutters, run-off areas, animal stock tanks, umbrella bases, any area around your home or stable where water stands. .

The Town of Silver City is using Bt in local storm drains, water collection basins, natural water drainage such as the San Vicente, Big Ditch, PA drainages and the Golf Course. Residents can purchase Dunks at our local nurseries and feed stores. Dunks also can be used as a preflood treatment in areas expected to become breeding sources.

Not Harmful to People or Pets. Bti does not harm people, pets, birds, fish, or plants. However, caution should be used to prevent eye contact and avoid open wounds when applying Dunks. See instructions on package for more information.

How to Use It. The dunks kill mosquitoes for 30 days or longer when placed in standing water outdoors. As the dunks dissolve, the Bti settles in the water where it is eaten by mosquito larvae. Dunks can be anchored with string to prevent them from being washed away. Alternate drying and wetting does not reduce their effectiveness. Use 1 dunk/100 sq. ft. of infested water.

How it Works.
Bacterial agents, like Bt, are effective in controlling insects in the larva stage only. The larva stage in an insects's life cycle is the stage during which most of the feeding occurs. Since, Bt must be ingested to work, the insect must be controlled during the larval stage. The larval stage is the stage in which the insect appears worm or caterpillar-like.

After Bt spores are ingested by larvae, they grow and reproduce, meanwhile producing crystalline toxins. The crystalline toxins paralyse the digestive tract of the larvae causing it to cease eating. Death will follow, but time of death can range anywhere from 12 hours to 5 days after ingestion This depends on the amount of Bt ingested, the size and variety of the larvae and variety of Bt used for control

West Nile Virus is a Community Concern.
Do all that you can do
Educate yourself and your neighbors
Eliminate standing water on your property.
Rid your yard of old Tires and other
Mosquito Breeding debris.
Together we can fight the bite