West Cook News

Sprays only kill adult mosquitoes that fly directly into the mist. Resting adults or mosquito larvae are not affected. The insecticide used in spraying dissipates within 1-3 days. Adult mosquitoes generally fly at dusk and dawn. Public health departments spray in the evenings during mosquito-borne disease outbreaks; spraying at other times is usually ineffective. However, spraying also kills lightning bugs, butterflies, and bees.

To effectively combat mosquitoes, it is recommended to target them with a safe agent while they are most vulnerable. The mosquito life cycle requires water containing decaying organic material for larvae to develop from their eggs.

Eliminating sources of standing water where mosquitoes could breed and placing larvicide in selected water-filled receptacles can interrupt the mosquito life cycle. Mosquito “dunks” available at hardware stores contain Bti spores from bacteria harmless to organisms that do not develop in water and have a highly alkaline gut. Most higher animals have acidic stomachs and are unaffected by Bti, while many insects do not have a larval stage that develops in water.

Steps to make a Dunk Bucket:

1. Use one to four five-gallon buckets (larger yards require more). If your bucket has a lid, cut or drill a sizable hole in it. Some experts recommend putting a stick or paint stirrer into the bucket so misguided mice and chipmunks can climb out. If there is no lid, place a net over the top with holes large enough for female mosquitoes but small enough to keep out birds and animals.

2. Fill the bucket halfway with water. It is beneficial for the water level to rise and fall over time since some species of mosquitoes lay eggs above the water line that hatch when the water rises above that level.

3. Add organic material such as straw or dried-out leaves that will decay in water.

4. Add ¼ to ½ of a Mosquito dunk (available at hardware stores). Each dunk lasts for 28-30 days.

Check every two weeks to ensure there is still water in the bucket and add another ¼ to ½ of a dunk every four weeks. If it develops an unpleasant smell, rinse the bucket and repeat steps 1-4 with different organic material.

Placement of Dunk Buckets:

Female mosquitoes prefer shady moist areas with standing water for laying eggs. Frequently empty other vessels with standing water like birdbaths or dog bowls since even small amounts of water can sustain mosquito larvae.

Bucket Considerations:

The bucket should be large enough not to dry out completely but small enough to handle easily—five gallons is ideal. Female mosquitoes prefer dark colors but any color bucket will work.

Mosquito Attraction Near Homes:

Placing dunk buckets near homes does not attract more mosquitoes as female mosquitoes seeking blood are attracted by carbon dioxide exhaled by humans and body heat.

Pools and Ponds:

Keep swimming pools properly chlorinated and garden ponds stocked with fish that eat larvae or use mosquito dunks if necessary.

Alternative Methods:

If you prefer not using dunk buckets, eliminate all standing water around your property, ensure window screens are intact, and consistently use DEET-containing repellents which deter various pests including ticks carrying Lyme disease.