Parasites and predators usually build up once a pest or host population becomes established. In some cases these naturally occurring controls are very effective in maintaining pest populations below economic thresholds. Pest populations are usually more prolific and, as pest density increases, it initiates the beneficial population development. Beneficial insect populations, however, can be purchased to supplement the natural populations and enhance control, thereby reducing the need for pesticide usage. Beneficials should always be purchased in either the egg or immature stage to assure the desired control.
Adults are capable of flying off to other areas.
Some beneficials can become a nuisance if populations become dense. Such a problem has developed in areas with the Asian lady beetle. Another example is the small braconid wasp that will infest catalpa worms when released to control hornworms in vegetables and tobacco. A list of supplies of various beneficials may be obtained from the Louisiana Department of Agriculture and Forestry. The use of beneficials for pest control is an integral part of the Integrated Pest Management and the Sustainable Agriculture Programs.