Beneficial organisms

A beneficial organism is an antagonistic organism that helps to control the population of an economically important pest. Beneficial organisms, also referred as natural enemies, can be classified as predators, parasitoids, pathogens, herbivores, and competitors. Natural enemies of insects include insects, non-insect arthropods, and pathogens.

Predators

A predator feeds on prey. Predators can be classified as generalist predators or specialist predators. Generalist predators include insects that feed on a variety of prey species, while specialist predators feed on a single or few prey species. Examples of insect predators are green lacewings, lady bugs, and assassin bugs.

Parasitoids

Parasitoids are insects that, as part of their development, live and feed in or on the bodies of a larger host, resulting in the host’s death. The immature stage of parasitoids is typically the stage to develop and feed on the host. Most parasitoids are wasps or flies, and a few are beetles.

Pathogens

Pathogens are microorganisms that infect and cause disease to a host. The disease debilitates or kills the host. Pathogens include nematodes, bacteria, viruses, fungi, and protozoa. Pathogens can be found naturally or are commercially available as biological pesticides.

Competitors

Competitors are organisms that actively compete with others for the same limited resources. The use of competitors for pest management is not very common.

Biological control

The use of biological control agents can be a key component of integrated pest management in agricultural crop production and other settings. In biological control, natural enemies are reared, released, or manipulated by humans in order to keep pest species at bay. The environment can also be influenced to enhance the establishment, sustainment, dispersal, and numbers of natural enemies.

There are three generally recognized forms of biological control: classical, conservation, and augmentation biological control.

Classical Biological Control

The goal of classical biological control is to establish a pest’s natural enemy by importing the natural enemy from its homeland into an area in which it is not already present. This type of control addresses invasive pest species introduced through immigration and trade. Invasive species cause little damage in their native range because they have natural enemies that keep their population in check. However, when the new habitat lacks natural enemies, invasive species can experience uninhibited growth and cause substantial damage. Researchers explore the pest’s place of origin in search of natural enemies. Once two or three natural enemies are identified and collected, they are tested in quarantine to verify that they will not become pests. Approved natural enemies are then reared and released into areas were the pest is present.

Conservation

The goal of conservation practices is to limit pests by influencing the environment to enhance the establishment, sustainment, dispersal and numbers of natural enemies. The following practices boost conservation biological control.

Identify insects to determine if they are beneficial or harmful and whether or not a control method must be adopted.
Reduce pesticide applications and time the applications to avoid killing natural enemies. In agricultural settings, this can be fulfilled by treating plants only when the damage is above a set economic injury level and spraying during times when natural enemies are not active.
Maintain ground cover and incorporate flowering plants and refuges. These materials can serve as a safe haven for natural enemies. Ground cover harbors natural enemies, while flowering plants and refuges offer alternative food sources, such as nectar, pollen, and other species to prey on, as well as shelter.
Such practices can be incorporated in agricultural settings by introducing cover crops attractive to beneficial organisms or planting flowering plants in windbreaks, hedgerows, and fencerows.

Augmentation

Augmentation involves the release of natural enemies into areas where they are already present. The organisms usually are obtained from commercial suppliers where they are mass produced and sold in their inactive stage. This control tactic works particularly well in enclosed situations such as greenhouses. Augmentation in conjunction with conservation can be used to maximize both types of biological control.

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