The International Organization for Biological Control (OILB) defines biological control as “the use of living organisms, or their products , to prevent or reduce losses or damage caused by harmful organisms.” From this point of view, this concept includes not only parasitoids, predators and pathogens of insects and mites, but also that of phytophages and weed pathogens as well as pheromones, juvenile hormones , autocidal techniques and genetic manipulations.
In any biological control effort, the conservation of natural enemies is a critical component. This implies identifying the factor (s) that can limit the effectiveness of natural enemies and modify them to increase the effectiveness of beneficial species. In general, conservation involves either reducing the factors that interfere with natural enemies or providing the resources needed by natural enemies in their environment , and these requirements can be access to alternative hosts, food resources for adults, shelters or microclimates adequate
The three main approaches to biological control
Biological control makes use of naturally occurring predators, parasites and pathogens to control pests. There are three main approaches to using natural enemies against unwanted populations of animals or plants.
1.Classic biological control (import): involves the collection of natural enemies of a pest in the region where it originated and that attack there and prevent it from becoming weed. New pests are constantly arising accidentally or intentionally and the introduction of some of their natural enemies can be an important means to reduce the level of damage they can cause.
2.Propagation: how to increase the population of a natural enemy who attacks a plague. This can be done by mass producing a predator in the laboratory and releasing it in the field at the appropriate time. Another method is the genetic improvement of a natural enemy that can attack or find its prey more efficiently. These predators can be released at special times when the pest is most susceptible and natural enemies are not yet present or can be released in large quantities. Propagation methods require continuous control and do not represent a permanent solution as can import and conservation methods.
3.Conservation of natural enemies: an important part of any biological control practice. This involves identifying any factors that limit the effectiveness of a particular natural enemy and altering them to assist the beneficial species. This approach involves either reducing factors that interfere with natural enemies or providing the required resources that will aid natural predators.
Advantages of biological control
- Incorporating biological control as part of an integrated pest control program reduces the legal, environmental, and public risks of using chemicals. Biological control methods can be used in plantations to prevent pest populations from reaching harmful levels.
- Biological control may represent a more economical alternative to the use of some insecticides. Some biological control measures may prevent economic damage to agricultural products. Most insecticides have a broad spectrum of action and non-specifically kill other ecologically important and potentially useful animals. Natural enemies usually have very specific preferences for certain types of pests and may not cause harm to other beneficial animals and people, with less danger of impact on the environment and water quality. When used properly, several commercial products for biological control can be quite effective.
- There are no problems with poisonings .
- The cost / benefit ratio is very favorable.
- The treatment with insecticides is eliminated substantially.
- They are natural products and are part of the ecosystem.
- Low toxicity
- Low or no pathogenicity on beneficial fauna.
- They do not generate resistance in pests.
- Easy and safe application.
- Easy establishment in crops.
- They contribute to the recovery of the biological properties of soils.
- While controlling some pests prevent the appearance of others.
- The resistance of pests to biological control is very rare.