Healthy lawns should require few, if any, insecticide treatments. Insecticides are only a last resort.
If you find that you need to use an insecticide, read the label carefully, take appropriate precautions, use as little as possible, and follow directions carefully. Keep in mind that almost all insecticides are hazardous to humans in one way or another, some are toxic to pets and wildlife, and most kill some of the beneficial insects along with the targeted ones.
Over the years, almost every major insecticide that was once thought to be safe has had either cautions or warnings posted. Many have been banned and for good reason. I’m a do-it-yourselfer, but this is one area that I call in the experts….and I’m not talking about the lawn care companies that send in a bunch of teenagers with a tank truck to drench your lawn.
Commonly used synthetic insecticides include:
- Dursban: Used for chinch bugs, cutworms, flea beetles, sod webworms, white grubs, armyworms, caterpillars, ticks, fire ants, fleas, wasps, mosquitoes, and ants.
- Diazinon: Used for billbugs, chinch bugs, cutworms, flea beetles, sod webworms, and white grubs & Japanese beetles.
- Orthene: Commonly used on cutworms.
- Sevin: Used for billbugs, white grubs & Japanese beetles, caterpillars, ants, fleas, mosquitoes, and ticks.
In addition, there are some botanical insecticides. These are derived from plants and natural sources, and can still be hazardous:
- Pyrethrin: Pyrethrin is derived from pyrethrin flowers and is a medium to highly toxic insecticide that will kill many different types (broad-spectrum) of insects at once. It is commonly used to spot-treat areas of a lawn. Try to avoid run-off into areas that contain fish, as it is toxic to them also. Commonly used on white grubs, armyworms, beetles, webworms, green bugs, and caterpillars.
- Neem: Neem oil is an extract from a neem tree. Neem is relatively low-toxic for animals and is used both for treatment and prevention, mostly for white grubs and caterpillars.
- Sabadilla: Sabadilla is derived from sabadilla plant seeds. It’s a relatively low-toxic botanical insecticide used on chinch bugs, webworms, armyworms, green bugs, and grasshoppers.
Biological insecticides are much safer, but also a bit more expensive. Biologicals include Endophytes, a fungus that grows in certain varieties of grass, and Bacillus Thuringiensis, commonly referred to as “BT”, is a bacterium that, when ingested, will destroy insects by eating at the inner lining of their guts. It is useful for sod webworms, armyworms, cutworms, and moth larvae. Another form commonly referred to as Milky Spore (Bacillus Popilliae) is used to control white grubs (Japanese Beetles).
Insecticidal soaps are a biodegradable treatment derived from salts of fatty acids. They are usually applied with water and soak the soil to kill the target insects. These soaps work by penetrating the cell-bodies of insects and are usually only effective on soft-bodied insects. Insecticidal soaps are commonly used for white grubs, chinch bugs, sod webworms, and billbugs.
Predatory insects are “good” bugs that eat “bad bugs”. Since most bugs are generally not a nuisance, it is important to understand that nature often has a way to balance itself out. Insects such as ants, ground beetles, ladybugs, wasps, big-eyed bugs, and even animals like birds can be helpful in controlling your “bad” bug populations by either feeding on, or parasitically attacking them. Many pesticides kill these predators if you’re not careful. If you have to use insecticides that can harm or kill these “good” bugs, try to limit the use (if you can) to spot-treatments on limited areas.