Reduce Pests Naturally with Biological Pest Control



Host: Good morning [evening, afternoon]. I’m your host __________. Farmers, do you know there are ways to control the pests and diseases that attack your crops without spraying chemical pesticides? Today we’re going to talk about biological pest control or how to reduce pests without using chemicals.


Host: First, what do we mean by biological pest control? Biological pest control means using one living organism to control another living organism. Let’s look at a little background.

Many centuries ago, Chinese farmers noticed that ants were eating the insect pests in their citrus orchards. The ants ate caterpillars, beetles and other pests. To encourage the ants to eat more pests, the farmers collected ant nests from trees in the countryside, and placed them in the orchards. The method worked! The ants were eating the pests, and keeping the pest population down. This was the first recorded example of what we now call biological pest control.

Today we know that most of the species of insects that we see in fields and gardens are not pests. In fact some of them are even doing important pest management work for you. We call these useful insects “beneficial” insects.


Host: Once you’ve identified the pest that is damaging your crops, you need to identify the beneficial insect that will control it. One common example of a beneficial insect is the lady beetle. Lady beetles eat aphids, whiteflies and other soft-bodied insects. Other beneficial insects include spiders, lacewings, wasps, praying mantis and dragonflies. Each of these can eat hundreds, even thousands, of insects in its lifetime. But they don’t damage crops.

The question that most farmers are probably asking is: how do I attract these beneficial insects to my field or vegetable garden?

The best way is to grow a variety of crops and plants together. Planting a variety of plants provides food sources for beneficial insects. For example, yarrow, dill, fennel and wild mustard are attractive to beneficial wasps, beetles and flies.


Host: It’s easier to increase the population of beneficial insects if you stop using chemical pesticides. That’s because chemical pesticides kill beneficial insects. They don’t just kill the bad insects! Some pests such as whiteflies multiply so fast that farmers end up spraying a lot of pesticide. But sometimes this makes the problem worse. Many insects build up a resistance to a pesticide – and then the pesticide no longer works.


Host: Work with the beneficial insects and other creatures that nature provides to control pests. It will take some time to find the right balance between pests and their natural enemies. This type of pest control does not get rid of every pest, but it will not harm the environment or your health.


  • Contributed by Belinda Bruce, researcher/writer, Vancouver, Canada.
  • Adapted in part from Developing Countries Farm Radio Network Package 36, number 6, Biological pest control: reduce pests naturally.
  • Reviewed by Hélène Chiasson, PhD, Codena inc., Saint-Charles-sur-Richelieu, Québec, Canada.

Information sources