Owen Yost

Several kinds of bugs actually control other kinds of bugs, efficiently and without harsh pesticides.

It’s natural and safe for whoever uses your lawn. Over the ages, Mother Nature has worked it all out.

The vast majority of insects in this world are harmless to humans. About 97 percent to 98 percent are beneficial insects. Only about 2 or 3 percent of all insects are pests.

Yet artificial pesticides indiscriminately kill absolutely everything: whether good, bad or just passing through.

Beneficial insects, on the other hand, attack only the insects that are our enemies. 

If you kill every bug in sight, you leave the door open for millions of bad bugs, which now have no natural enemies.

These bad bugs can cause direct damage — cutworms munching on your plants, for instance— or can be bothersome — as with aphids’ “honeydew” dripping on your car.

Insect pests are most common in what’s called monocultures; a farm with only one crop or a yard where one plant predominates, like a lawn.

Therefore, a wide diversity of plants is a key step toward ecological, safe insect control.

Yes, maybe there are little bugs on the leaves of your roses, but do you really know if they’re not vital to the plant’s health? Maybe they attract hungry birds, maybe they’re just lunching on some evil insects or maybe they’re spreading pollen around.

Not only is natural insect control safer, it’s a lot cheaper. In such a garden, you’ll witness nature doing her best work —  ladybugs and lacewings eating aphids by the thousands, birds eating grasshoppers and microscopic wasps killing borers. Microscopic worms in the soil kill fire ants, fleas and termites, which helps plants grow.

These beneficial insects work cheap — all they need is food. Spiderwort, goldenrod, clovers, lantana, sunflowers, thyme, fennel, asters, coreopsis, yarrow and gaillardia are just a few of the plants that provide food and shelter for beneficial insects.

Also, I strongly recommend the use of native plants in your landscape. Because of their genetics, our birds and butterflies recognize these before they’ll visit a plant that’s been brought here from another part of the world.

The most common beneficial insect is the ladybird beetle, or ladybug.

Ladybugs come in several colors — red, yellow, orange — and feed mostly on aphids, but also frequently make meals of thrips, scale insects, mealybugs, whiteflies and mites.

After you buy them, they’re best released in your yard around sundown at the base of infested plants.

Beforehand, spray your plants with water, liquid seaweed or sugar-water to give the ladybugs nourishment during the evening.

With this help, each adult ladybug will eat about 5,000 aphids. They also lay eggs on the outside of leaves.

Many stores sell packages of ladybugs, but avoid buying ones that are just sitting on store counters at room temperature because the bugs may be dead. Make sure they’re “domestic,” as some imported ladybugs can become pests. Also, spraying a chemical pesticide while they’re in your yard will surely kill them.

Beneficial nematodes are microscopic worms that live in the soil and attack soil-borne pests such as fleas, grubs, cutworms, ants — including fire ants —  and termites.

Almost all soils have a few already, unless you use a lot of pesticide or weed-and-feed fertilizer. You can also buy nematodes in many stores. Many people keep dog areas flea-free with them. Adequate soil moisture is essential for the worms to do their work, so water thoroughly before and after application.

Green lacewings are another popular beneficial insect. They’ll eat huge quantities of spider mites, aphids, thrips, corn earworms and other soft-bodied insects. Sprinkle them directly onto the plants that are suffering most. Release them at a rate of 2,000 per acre.

Trichogramma wasps are also very popular for insect control. They’re very tiny — four or five will fit on the head of a pin — and are harmless to humans. They’ll lay eggs in (and therefore kill) the eggs of webworms, hornworms, cutworms and many others.

These microscopic wasps are shipped to stores on small cards that look like sandpaper — pin the cards to a tree trunk or under the eaves of your house out of direct sunlight.

There are many other beneficial insects around. Ground beetles eat flea beetles, slugs, cutworms and leafhoppers. Mud daubers eat lots of spiders, crickets, flies and cicadas. Centipedes eat spiders and snails.

Braconid wasps are tiny black wasps that parasitize tomato hornworms, armyworms and cabbageworms.

Damselflies and dragonflies stick close to water features and eat lots of mosquitoes, gnats and aphids.

Beneficial insects deserve a try for their sensible ecological impact alone.

They were doing their job safely and efficiently long before any chemical companies opened for business.

They’re a lot cheaper and far more effective than indiscriminate, artificial pesticides that can harm anything that dares to be in your yard, including pets, butterflies, birds and small children.

OWEN YOST is a Landscape Architect Emeritus from the Denton area, and co-owner of Denton’s Wild Bird Center. He is a member of the American Society of Landscape Architects (ASLA), Keep Denton Beautiful, Audubon Society, National Wildlife Federation and the Native Plant Society of Texas. Reach him by e-mail at Yost87@charter.net .