The Homeowners Column

The Homeowners Column

To Spray or Not to Spray Pesticides

Photo of Sandra Mason

Sandra Mason
Extension Educator, Horticulture
slmason@illinois.edu

I loved cowboy shows when I was a kid. There was no question who were the good guys. The good guys wore white, nicely pressed clothes and the bad guys were in black. Secretly I thought it was a subliminal message that to be a good girl I had to stay clean. It didn't work.

When it comes to insects, the good guys are not so clearly identified. Many people believe the only good bug is a dead bug. Actually of all the species of insects in the world, very few are pests of people and our plants. Many are beneficial by eating or parasitizing the bad guys.

A common question from our clients is "I have this bug on my (fill in the blank). What do I spray?"

Pesticides are not the only answer in pest control. Pesticides can provide benefits, but if used improperly they can harm people, pets, and plants. If applied at the wrong time, they may be useless. Joe Toman, Extension Educator in Integrated Pest Management, offers some tips to the question - To spray or not to spray?

What's causing the problem?
The first step in an effective pest management program is proper identification. Many problems resemble pest damage but are caused by other factors. For instance, holes in leaves may be caused by late frost damage, or diseases, not by chewing insects. If it is a pest problem, identification of the pest is key to controlling it.

Fortunately, many resources are available for help with identification. You can purchase some great laminated cards suitable for use in the garden. The three sets include landscape pests, vegetable pests and beneficial insects. The cards can be purchased from U of I Information Services PH: 1-800-345-6087 at $7 per set.

Another resource are Master Gardener volunteers available through your local University of Illinois Extension Office. During the growing season Master Gardeners are available in many Extension offices to help in pest identification.

Plant problems or insects can be sent to the U of I Plant Clinic at 1401 St Mary's Road, Urbana 61802. There is a $12.50 fee per sample and place the insect in a vial of alcohol. No squishing. There are no road kill insect identification books.

If it is an insect causing the damage, does it really need to be controlled? The importance of controlling a pest varies with the situation. While hopefully you are willing to tolerate some weeds in your lawn or some spiders in your basement, certain pests present serious threats. Termites, for example, can cause major structural damage. However, large numbers of ants in the lawn rarely do any damage and have little relationship to the number of ants that enter the home.

How do I control it?
Before applying any pesticide, consider alternative management strategies. Many pest problems can be prevented. Use good horticulture practices, such as proper mowing and fertilizing to keep a lawn thick and healthy to prevent new weeds. Lawns can tolerate a few grubs. When lawns reach 8 to 10 grubs per square foot, then damage may be seen. Choose pest resistant plant varieties for the landscape to help prevent insects and diseases. Properly seal and caulk around windows and doorframes to prevent insects from entering the home. Often the use of pesticides is not necessary.

If the situation does require the use of a pesticide, be sure to read and follow the label recommendations. Choose the appropriate pesticide, the least toxic pesticide and the pesticide specific to that pest if available such as Bacillus products for damaging caterpillars. There are no silver bullets when it comes to pest control. Your best control measure is to arm yourself with information and some good phone numbers.

Mahomet Garden Walk is Sunday, June 25 from 11am-5pm.

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