Biological control is the use of living organisms to suppress pest populations, making them less damaging than they would otherwise be. Natural enemies of insects play an important role in limiting the densities of potential pests. These natural enemies include predators, parasitoids, and pathogens.
Biological control is an alternative to using pesticides and involves using one species or biological agent to control the population size of another species. The organism used is called a biological control agent. By releasing a natural predator into the crop growing area, the number of pests can be reduced.
This process is called biological control, and consists of using the pests' natural enemies, which can be other insects, bacteria, virus, nematodes, or fungi, to control the pest population.
Often, the natural enemies are found in the home range of the invasive pest. Some notable examples of classical biological control include the use of decapitating flies (several Pseudacteon species) against red imported fire ants, and a group of flea beetles, thrips, and stem borers used against alligator weed.
There are three primary methods of using biological control in the field: 1) conservation of existing natural enemies, 2) introducing new natural enemies and establishing a permanent population (called "classical biological control"), and 3) mass rearing and periodic release, either on a seasonal basis or inundatively.
Biological control is another one of the industry's viable pesticide alternatives and is an ecologically friendly pest management technique that uses 'natural enemies' to suppress pest populations. These natural enemies might include predators, parasites, or diseases unique to the pest in question.
Azadirachtin present in neem products is commonly used in biocontrol. The products are composed of extracts from fruits and seeds of the neem tree (Azadirachta indica). Its mode of action includes repelling many pests: mealybugs, aphids, nematodes, etc and preventing pests from laying eggs or feeding on plants.
Biological approaches can deliver on pest control while maintaining the safety of both consumers and workers. Low or no toxicity is a big advantage of biocontrol. This is especially true when considering the harmful residues that chemicals can leave on the crop.
Using them successfully in an IPM program takes great care. In some cases, biological control is more costly than pesticides. Often, the results of using biological control are not as dramatic or immediate as the results of pesticide use.
Integrated pest management (IPM) is widely recognized as the most effective and least toxic method for managing pest control issues.
Natural enemies are organisms that kill, decrease the reproductive potential of, or otherwise reduce the numbers of another organism. Natural enemies that limit pests are key components of integrated pest management programs.
Examples of least-toxic insecticides include insecticidal petroleum or plant-based oils, soaps, and the microbial insecticide Bacillus thuringiensis. Pesticides are used because they kill or control the target pest.
While neem oil has long been the go-to pest solution for organic gardeners, rosemary oil offers a more effective solution. Additionally, many gardeners find the smell of neem oil unbearable, and there are mixed opinions on whether neem oil is safe to use around pollinators.
Without the use of pesticides, there would be a 78% loss of fruit production, a 54% loss of vegetable production, and a 32% loss of cereal production. Therefore, pesticides play a critical role in reducing diseases and increasing crop yields worldwide.
The types of biological control
These are augmentative, conservation, and classical biological control. In augmentative biocontrol, growers increase natural enemies and pathogens in an area on a timely basis to fight pests and diseases. Natural enemies and pathogens are, for example, predators, parasitoids or microbes.
Biological control is particularly desirable because the tactic is environmentally safe, energy self-sufficient, cost-effective, sustainable, and can be readily incorporated into integrated pest management (IPM) programs. Furthermore, in many cases benefits from the use of natural enemies accrue at no additional cost.
There are many examples of successful classical biological control programs. One of the earliest successes was with the cottony cushion scale, a pest that was devastating the California citrus industry in the late 1800s. A predatory insect, the vedalia beetle, and a parasitoid fly were introduced from Australia.
But thousands of modern, high-yielding farms use no agricultural chemicals at all. The four Lundberg brothers of Chico, California, have a 2000-acre organic rice farm. Some of their fields have not seen a pesticide for 15 years.
Neem (Azadirachta indica)
The most effective insecticide comes from the seed, but the leaves can also be used. These extracts do not kill insects directly but effectively prevent their reproduction.
A good soil fertility program with ample water supply is seen as the first prerequisite for avoiding insect problems. Crop timing is often used to avoid certain pest groups. Crop rotation by family groups, resistant varieties, and floating row covers is used at some times.
In the paradox of biological control, simple predator–prey theory was used to show that the most efficient control agents caused the most extreme pest outbreaks, since efficient agents overexploited resources and died quickly, allowing pests to resurge in great numbers while agent populations slowly recovered5.
A famous example of biocontrol that went wrong is that of the Indian mongoose (Herpestes auropuncatus) which was intentionally introduced during the late 19th century and early 20th into over 60 islands mainly to control rats.
Biological control is a practical option for suppressing pest populations because: It is easy and safe to use. It is a very cost effective and environmentally sound method of pest control, especially compared to the use of broad-spectrum pesticides.