Biocontrol Agents

Biocontrol Methods

Biocontrol can be defined as the control of the type of living organisms with the application of another. Use of Biocontrol agents are also called biological control and are mainly used for the reduction of pest population and produce yields which are free of any pests. The biocontrol methods are a long-term method and most importantly, a self-sustaining one which helps in the control of invasive species of plants. Weed infestation and pests are controlled with the help of insects, pathogens and grazing animals. The natural animals in the form of parasitism, predation along with other similar mechanisms perform the role of biocontrol agents which help in maintaining the balance. 

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Types Of Biocontrol Agents 

Natural biological control can be done using two primary methods. inundative Biocontrol makes uses of pathogens. This approach makes use of pathogens that help to control the growth of weeds and is as effective as herbicides. Nematodes and nuts are most commonly used in inundative biological control and prevent invasive plants from implementation. Classical Biocontrol is another process which helps in the organic method of pest control. This method of Biocontrol makes use of the natural prey-predator relationship. In the classical Biocontrol, an eternal relationship is formed between plants and biological control animals.

Different Biological Control Agents 

Biological control agents' examples are given below:


Fungus, as a biocontrol method, forms a biological method of pest control. Fungi as a biocontrol method are considered a rapidly developing method and do not cause any harm to the environment. Fungi as a biocontrol method have proved to be a very effective alternative to chemical pesticides. Fungi as a biocontrol method are gaining widespread popularity in recent times. Entomophaga is a form of fungi which is effective against green peach aphid that forms a biological method of pest control. 


Predators are mainly free-living organisms which consume other animals in a large number of prey in the span of their lives. Considering insects majorly consumed crops, the ideal predators to act as a biological method of pest control are spiders, dragonflies, lacewings, etc.


The bacteria which belongs to the genus coccobacillus are more comparatively more pathogenic to insects and hence used for biological control. The bacteria infect insect's digestive tracts which limit the options for insects which have sucking mouthparts. Bacteria form a biological method of pest control. 


The creation of a virus which would selectively target pests and act as biological control is still under scientific research. These viruses would be specific regarding their hosts and would hence be effective biocontrol agents.


The parasitoids lay eggs in the body of their hosts which ultimately leads to the death of the host. The dead host is then used by the larvae as a food source as is one of the most prevalent methods of biological control.

Advantages and Disadvantages Of Biological Control 

The advantages of biological control ecology and applications are plenty. The biological control agents are environmentally friendly and do not have any side effects for humans. These methods are also comparatively cheaper than other Agrochemicals like pesticides and insecticides. These methods are also easy to use, readily available and can be used in any season throughout the year. The most crucial use of biocontrol agents is perhaps they help in reducing the use of chemicals and pesticides which have harmful effects for human beings. There are several other demerits of the use of biocontrol methods too. The use of biocontrol agents causes a significant and noticeable deterioration in the quality of produce. The biocontrol agents do not eradicate all the pests and are a useful and economical tool for pest control only when used on a large scale. 

Solved Examples

1. Why is A Fungus Used As A Biocontrol Agent?

Answer: Fungal biocontrol agents do not harm the environment and have proven themselves to be a cheap alternative to harmful chemical pesticides, and they also do not need to be ingested by the host but can invade them directly. They are an effective biological method of pest control. 

Did You Know? 

Aphiline refers to a braconid wasp which is used in controlling the aphid species from damaging crops.  Aphiline works with the use of stinging and parasitizing the comparatively small aphid species such as the peach aphid and the cotton aphid. The female wasp also lays eggs within the aphid, and the larvae that come out from the hatched eggs feed on the female wasp's body causing the aphid to be nothing more than a mummy on the crop.

FAQ (Frequently Asked Questions)

1. What Are Biocontrol Agents?

Biological control  is a method of controlling pests which includes mites, insects, weeds and organisms causing diseases in plants. The biocontrol method is often an essential part of an integrated pest management program. The classical process of Biocontrol involves the use of a natural enemy or predator, where a large population of predators is released to achieve control over the pest population. In the inoculative method, measures are adopted to control the level of natural enemies through regular administration. Pathogens, parasitoids, competitors are some of the methods by which the control of pests is brought about. Seed predators, plant pathogens and herbivores are used as biological control agents in many cases.

2. What Are Some Examples Of Biocontrol Agents?

Biocontrol agents are of various types which have their advantages and disadvantages. Predators are those who consume insects such as free-living species. Lady Beetles are examples of this category. The larvae of hoverfly eat aphids and are readily used. Parasitoids are organisms which lay eggs in the body of insects and thus help in controlling the pest population. Wasps and beetles are examples. The pathogenic microorganisms like bacteria and virus are also used in the process of Biocontrol. Bacteria attack the digestive tracts of insects, and an example of a bacteria used in Biocontrol is bacillus thuringiensis which is a soil-dwelling bacterium.