When you can’t flush, drain or clean out tree holes, ditches, low areas or drainage easements in your yard, you can use a larvacide product. Most home-use larvacide products are harmless to the environment and will not hurt people, pets or wildlife when used properly and according to label directions. These products can often be found at various hardware, garden and pond stores such as: Ace Hardware, Lowe’s, Home Depot, and Southern States.
A larvacide containing the active ingredient, methoprene, is a mosquito growth hormone regulator. It is sold under the following: STOP Mosquitoes from Breeding around your Home! Brand names: Altosid, Altosid XR, Prestrike, Zodiac. It changes the life cycle of the mosquito so it will not hatch out from its aquatic form. The mosquito never matures into a biting adult. This product is virtually non-toxic to fish, mammals and insects other than flies. It can be used in numerous environments because of its low toxicity.
A different kind of larvacide, which is a biological treatment, contains the bacteria Bacillus sphaericus (Bs). It is sold under the following brand names: Vectolex, Mosquito Bits. It is a corncob granule that contains the bacteria. These bacteria dissolve off the granules into the standing water. The released bacteria infect the gut linings of the mosquito larva, eventually killing it. This product has a month long residual and is only toxic to other aquatic flies such as black flies, midges, and no-see-ums.
Bacillus thuringiensis israelensis (Bti), is another biological treatment. It acts in much the same way as Bacillus sphaericus. It is sold under the following brand names: Vectobac, and Mosquito Dunks. Vectobac is the concentrated solution of the bacteria that you can put in the water. Mosquito Dunks are the solid doughnut-like forms that float on the surface of the water and have a residual for up to 30 days. Some fish, like top feeding minnows and mosquito fish species, are good eaters of mosquito larvae and pupae. This is the perfect way to stop mosquitoes from breeding in your ornamental ponds.
For more updated information, contact your local health department, or you can click on this link for the Center for Disease Control