Yard lizards can be injured or killed by pesticides.

Is Bayer Lawn Insect Killer Harmful to Lizards?

by Audrey Lynn

While many insects in the grass are more ugly and icky than dangerous to your lawn's health, those that bite or sting and the ones that can easily move from the yard to your home need to be dealt with decisively. Pesticides for use on lawns, such as Bayer Complete Insect Killer for Soil & Turf, can eliminate the creepy-crawlies, but may also injure or kill beneficial insects and other living things in the yard, including those cute little lizards that like to climb on fences and hunt for prey in the grass.

1. How It Works

Bayer insecticides for lawns work both on contact and via ingestion. The label states the product kills surface insects such as fleas, ticks, spiders and flies within 24 hours, and kills grubs, army worms and other soil-dwelling insects for up to three months. The ready-to-use hose-end spray bottle, concentrated liquid and granulated formulas all contain the active ingredients imidacloprid and b-cyfluthrin.

2. Properties of Imidacloprid

Imidacloprid is listed on the National Pesticide Information Center's website as not very toxic to birds and only slightly toxic to fish. It is moderately toxic to humans and other mammals, and highly toxic to honeybees. Some topical flea treatments used on dogs have imidacloprid as an ingredient, and the website states some humans suffer contact dermatitis when the chemical is present on their pets. Lizards can be poisoned by coming into contact with imidacloprid, through grooming themselves to get the poison off, or by eating bugs and insects that have imdiacloprid on their bodies or have ingested the poison themselves.

3. B-Cyfluthrin Properties

Beta-cyfluthrin is a synonym for cyfluthrin, according to the California Statewide Integrated Pest Management's pesticide database. The chemical is highly toxic to birds, aquatic life and honeybees, but only slightly toxic to people and other mammals. Like imidacloprid, b-cyfluthrin acts as both a contact poison and a stomach poison, so it may injure or kill lizards that ingest the insecticide or get it on their skin.

4. Safety for Pet Lizards

There is no way to herd wild lizards out of your yard to keep them safe, but if your kids have pet lizards, they should not go into a treated area of the yard to collect crickets and other crunchy insect treats for their pets. If a pet lizard is normally allowed some time outside, keep it indoors until the treated area is safe to enter.

5. Applying Pesticides

You can use a mechanical spreader to apply granular insecticide to the lawn. The spreader evenly distributes the granules. Water the lawn thoroughly within 24 hours to thoroughly apply the insecticide into the soil. Attach the ready-to-spray bottle to your hose and, making sure the dial is set to "off," turn on the water. Walk to the farthest point in the yard and turn the sprayer on, applying an even coating of pesticide to the lawn. The grass should be wet, but not to the point of runoff. Spray with a back and forth motion, working your way back to the faucet. You can dilute 1.5 tablespoons of concentrated insect killer with 1 gallon of water in a handheld or backpack pump sprayer. Spray the lawn as directed for the hose-end sprayer. Once the treated lawn is dry, it is safe for children, pets and lizards -- as long as none of them eat anything they find in the grass.

6. Insecticide Alternatives

Lizards eat spiders and other insects, making them a valuable addition to the yard. They, along with beneficial insects lizards may not eat, can help keep the yard clear of harmful pests, which may render pesticides unnecessary.

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