What Is Biological Pest Control?

Pests aren’t just those pesky insects that invade our homes. They could be plants, like the weeds that compete with our precious plants for nutrients and space. Pests could also include the rodents that infest our homes or feast on our plants.

The use of insecticides and pesticides for controlling pests has proven effective over time. But they often come with consequences. Synthetic insecticides and pesticides can contaminate the soil and negatively affect the plants you’re trying to protect.

This eventuality gave rise to organic means of controlling unwanted pests, which don’t pose any threat to us, our plants, or the environment at large. Another quite potent method of pest management is biological pest control. Do you want to learn more about it?

What Is Biological Pest Control?

Let’s assume that you have a rat or mouse infestation in your home. You then decide to get some cats. Wouldn’t that be a smart move?

Cats are natural predators of rats and mice. So, getting cats is your way of keeping those little intruders in check. They won’t run around as much once they notice the presence of cats.

If they choose to come out in the open, you can rest assured that your cats have you covered.

This is the typical way that biological pest control works. By definition, biological pest control is a method of controlling pests, such as weeds, insects, or even plant disease, by using other organisms. This approach is often used in integrated pest management. It involves the introduction of natural predators, parasites, or even competitors, to keep the errant pests in check.

Biological Pest Control Strategies

There are some strategies for implementing biological pest control. Let’s take a look at them.

The Importation Strategy

This method is also often called classical biological control. It involves introducing the natural enemies of the pests you want to control. These enemies are often brought in from another place if they don’t occur naturally occur in the environment you need them.

Though quite effective, this method requires close monitoring. It’s important to be able to control the environment with the newly introduced agents. The best effects occur when the control agent doesn’t have long-term persistence. This keeps its population in check even when the pests you wanted to control are no longer present. If you don’t consider this, there’s the risk that the biological control agent will get out of hand and become a serious pest itself.


One good example of this strategy is the introduction of parasitic wasps to control aphids. These wasps lay their eggs inside aphids, which eventually die when the larvae emerge. Over time, this can reduce the aphid population on farms.

Another great example is introducing entomopathogenic nematodes to control vine weevils. These nematodes release bacteria into the soil, which in turn, attacks and kills the vine weevils.

The Augmentation Strategy

This strategy is similar to the previous one in the sense that it involves the introduction of a pest’s natural enemy. But in this case, the release is gradual, to keep the pest population from increasing. This inoculative release is a long-term control method that keeps the pest population from increasing. This is more of a preventative method than a curative one.

An initiative release, on the other hand, involves setting loose a large population of pest control agents in hopes of rapidly eliminating the destructive pests.

Some good examples of this approach occur in greenhouse farming where they release parasitic wasps to control whiteflies. To control the population of the two-spotted spider mite, farmers periodically release a predatory species of mite. 

Trichogramma are insect egg parasites. They’re released as an attempt to control the moths that affect plants. These parasites feast on the moths’ eggs, preventing them from becoming adults and consequently reducing the moth population.

The Conservation Strategy

This third approach is a way of maintaining your biological control agents. After the natural enemies of the pests have adapted to the environment and the pests, you encourage them to stay. This method is ideal for maintaining long-term control since the control agents will continue to be present to keep the pests in check. This is the third strategy for controlling pests with other insects.


Typical examples include the practice where nectar-producing plants are grown around rice fields to keep planthoppers’ predators around. This method is so effective that the farmers have had to use fewer insecticides while harvesting more grain.

The Advantages and Disadvantages of Biological Pest Control

Biological pest control has proven to be effective in most cases, which is why it’s still in use today. But as effective as it is, it has its own pros and cons, which we’ll discuss below.

The Advantages

One obvious plus that comes with the use of biological pest control is its safety. Unlike synthetic pesticides, it won’t leave hazardous residue behind. There are no chemicals that could leach into the groundwater and it doesn’t create resistant insects. This is an all-natural approach to pest management on all levels.

The Disadvantages

To successfully implement biological pest control, researching and studying the different variables that might affect its efficacy is important. If this isn’t done properly, a lot could go wrong. The entire activity might end up being a waste.

Keep in mind!

You’ll need to invest a lot of time and money to carry out this approach. The cost of choosing, testing, studying, and breeding biological control agents can often be high.

You also have to be careful when matching a bioagent with a pest. There are cases where only one particular bioagent will be effective against a certain pest. This choice can be quite tricky. If you get it wrong, you could be wasting a lot of time and money.

There is also the need for skilled manpower. The more detailed and precision-dependent an activity is, the more skill you need to carry it out. The same applies to biological pest control. Without the right skill levels in the right places, a lot can go wrong.

There have been cases where imported bioagents ended up becoming pests themselves. One good example is the introduction of the Indian mongoose to Hawaii. It was imported to control rats and snakes in the sugarcane fields. It eventually became a pest that preys on Hawaiian amphibians, poultry, and reptiles.


Biological pest control is a great way to keep pests in check, but a lot could go wrong if the right things aren’t done at the right time.

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