What is Biological Control?Biological control is a natural method of reducing pests that uses their natural enemies rather than harmful chemicals or pesticides. These natural enemies, also called biological control agents, include predators, pathogens and parasitoids. By using these natural methods of pest control, we can all reduce and even eliminate the use of environmentally damaging types of pest control. Don Kuperhand, Organic Technology Director for Organic Pest Control NYC says "When working with the delicate ecosystem of a garden or crop field, finesse is key. With biological control agents, we are able to zoom in on problematic pests without causing harm to the surroundings that we want to preserve. This is an extremely powerful strategy as it employs both laser precision targeting of the problem pest, while maintaining the health of a garden or crop and done so in a way that is in agreement with mother nature. Using natural enemies to control pests, while may require some trial and error initially, is worth the effort to sustain a healthy ecosystem. We are able to alleviate a problem without the use of harmful chemicals which would otherwise exacerbate the situation further."
Agents of Biological Control
Predatory InsectsLady bugs do more than just provide children with endless hours of catching and releasing entertainment. Insects such as ladybugs, lacewings and the praying mantis eat harmful pests in very large amounts as part of their daily diets.
PathogensPathogens such as fungi, viruses and bacteria can make pests sick, just like they can humans. Choosing and releasing a pathogen that is designed to specifically attack a harmful insect group in your crop can efficiently eliminate these nasty pests.
ParasitoidsThese creepy creatures resemble the nightmare scene from Aliens. As they develop past their larval stage, they kill their insect hosts. Certain flies and wasps start their life cycle in this grizzly way, thus eliminating your garden of its insect enemies one unwilling host at a time.
What Makes the Best Biological Control Agent?The best biological control agents reproduce easily, are very specific to the intended pest that needs to be controlled, and will easily adapt to many different climates and conditions. It is also important that this natural enemy is active at the same time that the pest is active. Of course "agents" aren't limited to just insects. Take for example, the relationship between the chicken and the fruit fly. The chicken breaks up the lifecycle of the fruit fly, which increases the health of the ecosystem and prevents damage to fruit and fruit trees.
Types of Biological Control
ConservationConservation focuses on preserving your pests' natural enemies that already exist in your environment. This is one of the most important and easiest forms of control as the natural enemies that are already present are already adapted to your environment. This cost-effective method's biggest requirement is simply careful thought and planning. For instance, if you find that it is absolutely necessary to use a pesticide in your garden or crop, taking care to select the most targeted product that has the least impact on other species will ensure that your crops' natural helpers don't suffer the same effect as its pests.
Classical Biological ControlSometimes a garden or crop pest is one that doesn't naturally occur in your environment. These exotic invaders make their way to a new place and thrive due to the lack of natural predators that exist in their original home. In order to bring these pests back down to manageable levels, their natural enemies can be imported as well. If they can learn to thrive in the same environment as your unwanted pests then the pests will no longer have an advantage. This long-lasting and inexpensive method requires little maintenance once the initial set-up efforts have been made. Simply taking steps to ensure that the new natural enemies are comfortable and able to thrive in their new home will keep them active and reproducing season after season.
AugmentationThis last control consists of simply releasing more of your already occurring natural enemies. For instance, if your tomato plants are overrun by aphids, releasing a fresh crop of ladybugs will please both the plants and the hungry little cuties (not to mention the kids). Augmentation can also be achieved by enhancing the environment to provide additional beneficial food sources and shelter for your friendly little helpers. For instance, mixed plantings and flowering borders can enhance your natural enemies' environment by providing additional sources of pollen nectar and varied sources of shelter. But be careful with this method, as plant pairings and borders must not become sources of enhanced food and shelter for your pests as well. A great example of this method is planting calendula as a border plant. It will attract beneficial ladybugs while repelling the nastier pests!
How to Best Implement Your Biological ControlsOf course, all of this intricate planning will benefit you and your crop very little unless done the right way. Releasing your little helpers at the right time and into the right environment is key to successful biological control. Research your target pest, its natural enemies, their life cycles and your own environment to ensure that you are making the right choices for your crops. This way, you will prevent your careful purchase from simply dying upon release or making its way to a more friendly environment where it won't do any good for your crop. Knowledge is the tool that will benefit your crop most of all.
Image credit: Jan Stipala, via newscientist.com
Michael Bonds is a consultant for an NYC environmental firm that focuses on organic approaches in pest management and green sustainability, Organic Pest Control NYC. He enjoys exploring alternatives to traditional approaches and going green wherever possible.
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