The Limits, Dangers of DIY Pest Control

Old Flit sprayer

Why spend money on an exterminator to get rid of bugs when you can simply squash them, spray them, or trap them? After all, there are hundreds, if not thousands of products on the store shelves to kill pests, right? Wrong! Pesticides are poisons, and when used improperly can make a small bug problem even bigger. Even worse, some of those chemicals are deadly! You may think you’re saving a few bucks, but the dangers of DIY pest control outweigh the benefits.

The Wrong Treatment

That insecticide you’re spraying may be enough to scare the pests away, but not strong enough to kill them.

Jon Traunfeld
Jon Traunfeld

This is especially true if you’ve misidentified the pest. One example is the carpenter ant. It’s not just annoying like most ants, it’s bigger and downright destructive. They’re also tougher to kill. They build their nests inside the wooden structures of your home, causing extensive damage. They’re bigger than most ants and harder to kill. The worst thing you can do is spray an over-the-counter insecticide. “This just causes the ants to scatter and create new colonies, with a few new queens,” says extension agent Jon Traunfeld with the University of Maryland. You can easily turn a small problem into an infestation.

Carpenter ants, like bed bugs, often need a professional exterminator to locate the parent colony and destroy it. The pros often use an industrial bait that the ants will take back to the queen, and kill the others in the nest.

Pesticide Danger

Researchers at the National Institute of Environmental Health Sciences estimate that more than 20,000 people go to the emergency room each year because of pesticide poisoning. Between 20 and 40 of the injuries are fatal.  The reason? No pesticide is utterly safe. The same chemicals that destroy an insect’s nervous system also have a negative effect on humans and pets.

Some people are injured by inhaling the chemicals while spraying in cramped crawl spaces or underneath the house. This doesn’t take into account the number of people stung while trying to remove a wasp or hornet’s nest. There’s a reason the pros wear that protective equipment!

Instructions, What Instructions?

Malathion application instructions.
Malathion application instructions. Credit: Chris Alberti, CC 2.0.

Even dangerous pesticides can be handled safely … if only we would stop to read and follow ALL the directions on the label. But many of us are too lazy, don’t think we have time, or come up with several other excuses not to read them. In our defense, the instructions on most items are hard to understand, but reading them is critical, especially instructions on pesticide labels.

Killing Good Bugs

Lady bugs devour a slug
When lady bugs attack: This slug doesn’t stand a chance. Credit: Steve Jurvetson, CC 2.0.

Many bugs such as roaches, ants, bedbugs, and silverfish have the “ick” factor. Just the thought of them inside your house makes your skin crawl. Many of us panic and reach for the spray can when we see any kind of bug outside, be it grubs or ladybugs. Yes, some bugs are destructive to your plants, trees, and lawn. (The emerald ash borer and aphids come to mind.) But when you spray a one-spray-kills-all pesticide, you also endanger the beneficial bugs. The praying mantis will take care of those crickets and moths for you. A ladybug will eat 50 bugs a day. That’s why Traunfeld says we should let nature take its course. “If we didn’t have aphids, we wouldn’t have ladybugs,” he says. “We want to encourage biodiversity above ground and below ground. If you see a few grubs, don’t panic. Let the birds and other insects take care of them.” In other words, the beneficial bugs and other wildlife need something to eat.

Alternatives to Pesticides

If you really want to keep the bad bugs out of your yard, try planting pest-repelling plants. Marigolds will discourage mosquitoes, plant lice, and rabbits from your garden. Plant basil outside and inside to repel mosquitoes and house flies. Chrysanthemums will take care of the ants, roaches, Japanese beetles, ticks, and silverfish. And most bugs will stay away from lavender and mint. These plants won’t kill the pests, but they should keep them out of your garden, and they smell a lot better than pesticides.

Yes, there are times the bad bugs will outweigh the good ones. That’s the time to call in a pro. You’ll likely spend less money on an exterminator than having to repeat the process of using the over-the-counter remedies. And if they’re certified, you can be sure he or she has read the instructions on those chemicals.

Jon Traunfeld is the director and state master gardener coordinator for the Home and Garden Information Center and extension specialist at the University of Maryland. He focuses on home gardening and pest management. He has appeared on “The Martha Stewart Show” and in The Baltimore Sun and The New York Times.

Brenda Ryan

Brenda Ryan

Brenda Ryan is a former radio newscaster and journalist who writes for LawnStarter’s blog pages. In her free time she enjoys traveling, gardening, visiting wineries, and running 5K and 10K races in her home state of Colorado.