Some insects can help solve pest problems on farms and in gardens.(Battle of the Bugs)

You’re a farmer with a big problem. Your farm has been invaded by pests. Grasshoppers are chewing your corn plants. Aphids are sucking sap from your pea plants. Weevils are gnawing holes in your pepper blossoms. Stalk borers are burrowing into the stems of your squash plants.

How are you going to solve your problem? Well, you just might want to bring in more insects! In nature, many kinds of insects kill other insects. In this way, the populations of certain kinds of insects are kept under control.

Today, many farmers and gardeners control pests the natural way. They are learning how to use helpful insects to control the number of harmful insects that attack their crops.

Take a look at the insects shown here. They should be very welcome in gardens and on farms. Why? These helpful insects kill many kinds of crop damaging pests. Here’s how they do it.

Ladybugs and praying mantises are the lions and tigers of the insect world. These hungry hunters have chewing mouthparts, which they use to devour many kinds of garden and crop pests.

Assassin bugs are hunters, too. But these bugs have sucking mouthparts. An assassin bug holds its victim, or prey, with powerful front legs. Then the assassin bug uses its long, curved beak to pierce its prey and suck out its body fluids.

Some kinds of female wasps kill pests in another way. These wasps lay one or more eggs inside the body of an insect pest. When the egg hatches, the larva-or young feeds on the insect’s internal organs, killing it from the inside out.

Integrated Pest Management

As you learned, many farmers are beginning to think that they can’t solve pest problems with chemicals alone. Pesticides are getting expensive and they don’t always work.

Some farmers are trying a different strategy Integrated Pest Management, or IPM for short. It works like this. Farmers use a combination of ways to control insects. That’s what the word integrated means. Some of the methods that are parts of IPM are shown in the diagram.

IPM is not easy. Farmers who use IPM must have a great deal of knowledge about both plants and pests. Farmers must also make careful, often difficult, choices. For example, when farmers find insect damage in their fields, they must decide what to do. Will biological control work or should a pesticide be used?

Whenever possible, farmers avoid using chemicals to kill crop-damaging insects. They also try to avoid using weed killers, or herbicides (her ba sids). Instead, farmers control weeds by pulling them out.

In Indonesia, the government gave rice farmers a crash course in IPM. Farmers were spraying pesticides on their rice paddies up to eight times a season to kill pests called plant hoppers. The more they sprayed, the more plan hoppers there were. The pesticides were killing spiders that eat plant hoppers!

So, the government banned many kinds of pesticides and taught the farmers ways to bring back the spiders. In three years, farmers were using 90 percent less pesticides. What about the spiders? They were back at work, eating plant hoppers.

Praying mantis

Eats most kinds of insect pests, including weevils, grasshoppers, aphids, and stalk borers.

Ladybug

Eats mainly aphids, but also eats stalk borers, weevils, whiteflies, and Colorado potato beetles.

Braconid wasp

Lays eggs inside the larvae of cabbage  looper moths, grain weevils, cabbage butterflies, and tomato hornworms.

Assassin bug

Attacks many kinds of leafhoppers, caterpillars, and aphids, as well as Colorado potato beetles.