Mosquitoes lay there eggs on the surface of standing water and stick around while the eggs develop. The mosquito larvae will hatch in about a week. If you’ve an area of soil that doesn’t drain well and retains water, mosquitoes will lay their eggs there also. Other mosquito breeding grounds include long standing water-filled rain barrels, bird baths, containers, tubs, flower pot trays, vases, old tires, clogged roof gutters, sewer drains, streams, ponds, and vernal pools.
To decrease the mosquito population, and lessen the chance of West Nile Virus spreading, be sure not to let water stand for more than a couple of days in any of the above mentioned areas. Mosquito Dunks are effective in killing mosquito larvae for 30 days when added to standing water. The dunks which are formed in the shape of small donuts consist of bacteria known as Bti israeliensis. Mosquito Dunks only kill mosquito and black fly larvae, which die within 24 hours of ingestion. Mosquito dunks will not harm people, pets, wildlife or fish.
You can buy Mosquito Dunks at local garden centers. Bti israeliensis also comes in a granule (grits) form, but the donuts are more readily available. Dunks can be broken up easily into smaller pieces or crushed to a granule consistency. One dunk is effective in up to 100 square feet of water.