Biological Control

Biological control (biocontrol) is an alternative to pesticide use that relies upon natural enemies to suppress pest populations. Biocontrol is a set of methods to control pest organisms by using natural ecological interactions including predation, parasitism, and competition. It includes the intentional introduction of predators, diseases, or other parasites of a pest. For example, ladybugs are common predators of many plant-eating pests. It is possible to buy quantities of ladybugs for release in home gardens or farms. The hope is that these ladybugs will feed on pests and reduce their abundance.

There are many specialized and effective biological controls. One of the most effective is a bacterial disease, Bacillus thuringiensis, which kills larval forms of many insect pests, including many caterpillars. It is used widely.

Another technique to control insects involves the use of sex pheromones, a chemical usually releases by the female insect, acts as an attractant to members of the opposite sex. These chemicals have been identified and synthesized and used in insect control as bait in traps. In some species it has been shown to be effective up to 4.3 km away. Since many moths are pests, synthetic odors can be used to control them. Spraying an area with the pheromone confuses the males and prevents them from finding females, which results in a reduced moth population the following year.

Biocontrol has also been successfully used to control certain terrestrial and aquatic weeds.