What is Biological Control?

About the Program

The Biological Control Program is an integral component of the Plant Health and Pest Prevention Service's (PHPPS) Pest Prevention Program. The program helps to minimize the economic and environmental impact of noxious weed and insect species through the implementation of biological control programs throughout the state. Implementation requires the rearing of appropriate natural enemies and their release and evaluation in agricultural, natural and urban environments.

Biological control is the use of natural enemies (predators, parasitoids, and pathogens) to reduce densities of insect pests and weeds. Releases of natural enemies may be made once resulting in permanent establishment, or it may be necessary to continue to make augmentative releases. It is a global scientific strategy for managing pests that has been conducted for over 100 years and has resulted in many successful programs. The reason biological control is so effective and safe is that a high degree of host-specificity for the targets is sought before a potential control organism can be released into the environment. This protocol ensures that effects on nontarget species are minimized and that the agents are likely to be efficacious.

There are several steps involved in implementing biological control. Each step in the process is linked with previous steps and requires a strong scientific base. These steps are as follows:

  • STEP 1. Accurate identification of the pest species and confirmation of the pest as a target for biological control.
  • STEP 2. Surveys for co-evolved natural enemies are conducted in the area of origin of the pest (usually overseas).
  • STEP 3. Demonstrate host-specificity of potential control organisms and apply to USDA for a field release permit.
  • STEP 4. Following approval from federal and state regulatory officials, biological control agents are shipped to a domestic quarantine facility where they are examined to confirm species identity and to determine whether they are free of parasites and diseases.
  • STEP 5. Once released, each biological control agent is evaluated for establishment, spread, impact on the target species, and impact on nontarget species. Careful, long-term evaluation studies provide scientific data that are used to improve current and future programs. Additional releases may be made in an augmentative manner in systems where long-term stability of the natural enemies is not feasible.

Despite the effectiveness of the PHPPS's Pest Prevention Program, new pests will become established.

Many of these pests will cause significant agricultural, natural and urban losses at pest population levels where current conventional control methods are prohibitive in cost or lack effectiveness.

The costs of controlling these pests utilizing conventional pesticides will continue to increase and it is quite possible that some widely used pesticides may be found unacceptable due to environmental or health and food safety considerations.

Historically, biological control has provided cost-effective and environmentally benign long-term control of pests.

Each year in California, at least five new exotic insects, as well as additional noxious weed species, become established. Eradication of some of these species is not always feasible, due to either the rapidly expanding distribution of the pest or constraints regarding the tools available to attempt eradication. Many of these exotic invasive species cause significant economic damage to the agricultural industry of the state, as well as negatively impacting the urban and natural environments. Conventional pesticide treatments are not always practical, and therefore, alternative methods to chemical treatment of exotic and other noxious pest species must be employed to protect our agricultural economy and the urban and natural environment.

Biological control provides a proven long-term regional solution to mitigate the economic impact of some agricultural pests. Establishment of natural enemies of exotic insect and weed pests can provide a permanent reduction in pest population densities and substantially reduce their economic impact. For example, since the introduction and establishment of a natural enemy of the Ash Whitefly in 1989, populations of this pest have been kept at low levels resulting in substantial annual savings in pest control costs. Generally, successful biological control programs result in benefit-cost ratios exceeding 100 to one.

The Biological Control Program was established during the 1973/1974 fiscal year to develop alternatives to traditional control and eradication methods used by the PHPPS.

Biological control technology provides a response to the increasing public demand for a change from conventional pesticides to biological techniques for control and management of certain pests. The Biological Control Program integrates with the mission of the PHPPS through the development and implementation of biological control and related techniques to be used independently for controlling pests, or integrated with other strategies to control pests.

There is no other program in the state that currently allocates all of its resources and expertise towards applied biological control. The University of California devotes its primary efforts to basic biological control research. It is not economically profitable for private industry to develop classical biological control programs. Federal agencies do not have an implementation network in California to facilitate applied biological control programs.

Statutory authority for the program is provided by the following sections of the Food and Agricultural Code:

Section 403: The Department shall prevent the introduction and spread of injurious insect or animal pests, plant diseases, and noxious weeds.

Section 405: (a) With the prior approval of the Department of Fish and Game and the Office of Environmental Health Hazard Assessment, the Department of Food and Agriculture and the Department of Pesticide Regulation may reproduce or distribute biological control organisms that are not detrimental to the public health and safety which are known to be useful in reducing or preventing plant or animal damage due to pests or diseases.

Section 431: The Department shall collect and preserve books, pamphlets, periodicals, and other documents which contain information that relates to agriculture.

Section 432: The Department shall collect and prepare statistics, charts, films, photographs, and other illustrative or exhibit material and information which shows the actual condition and progress of agriculture in this state and elsewhere.

Section 433: The Department shall correspond with agricultural societies, colleges, schools, the commissioners, and with all other persons who are necessary to secure the best results to agriculture in this state.

Section 434: The Department shall issue and cause to be printed and distributed to the commissioners, and to such other persons as it may deem proper, bulletins, charts, photographs or other illustrative material or statements which contain all the information which is best adapted to advance the interest, business, and development of agriculture in the state. The Department may broadcast such portions of the illustrative material or statements as are adapted to give effect to this code. It may exhibit or display such data and material as have been collected or prepared and may incur expenses which are necessarily incidental to the exhibit or display of such data and material.

Section 461: The Department may conduct surveys or investigations of any nursery, orchard, vineyard, agricultural commodity, agricultural appliance, farm, or other premises within the state liable to be infested or infected with any pest as defined in Section 5006 or disease, including any infectious, transmissible, and contagious diseases of livestock and poultry, for the purpose of detecting the presence of, or determining the status of, the pest or disease.

Section 482: The Secretary may enter into cooperative agreements with individuals, associations, boards of supervisors, and with departments, bureaus, boards, or commissions of this state or of the United States for the purpose of eradicating, controlling or destroying any infectious disease or pest within this state. He or she may enter into cooperative agreements with boards of supervisors for the purpose of administering and enforcing this code.

The California Department of Food and Agriculture's (Department) mission is to serve the citizens of the state by promoting California agriculture and fostering public confidence in the marketplace through the development, implementation and communication of sound public policies and programs. The Biological Control Program plays an integral role in supporting this mission by colonizing new natural enemies for suppression of exotic pests thereby providing economic and environmental benefits to all the citizens of California. On average, five new exotic insects establish permanent populations each year in California. For every dollar spent on a new biocontrol agent, at least 23 dollars are saved in the economy. Biological control also serves as an environmentally friendly alternative for the control of noxious pests.

The Biological Control Program also benefits the PHPPS's Pest Prevention programs. It provides information and consultation on the biology and potential for biological control of serious pests. Such information assists the PHPPS in fulfilling the Department's responsibility to prevent the introduction and spread of injurious insect or animal pests, plant diseases and noxious weeds. As a result of this interaction, the PHPPS can make decisions based on the best available information, balancing the need for controlling serious agricultural pests with pesticides, while protecting the environment from the adverse impact of these products. The inclusion of biological control alternatives in Pest Prevention programs helps to ensure a continuous, plentiful supply of agricultural products that are safe for the consumer, the environment and agricultural workers.

The Biological Control Program directly benefits the general public and consumers because it implements pest control strategies that produce minimal disruption of the environment, and reduce pesticide use. These efforts reduce the potential incidence of direct and indirect exposure of people as well as the natural environment to pesticides.

Several partnerships have been formed with agencies interested in biological control of pests. Cooperative program operations are a direct indication of the wide spectrum of interest and importance in biological control programs. Cooperative relationships reinforce communication and increase public confidence regarding our commitment to biological control.

The program is comprised of four permanent scientific and technical and two temporary employees. The permanent staff has expertise in planning, organizing and implementing biological control programs. In Fiscal Year 2020, the program was funded at a level of approximately $1.2 million. The General Fund accounted for 51 percent of this total, supplemented by federal funds. Program activities are organized within a framework of functions and the procedures we engage in to perform them. Each project is ultimately directed toward meeting our mission, which is to protect California's agricultural, natural and urban systems through the use of natural enemies.

FUNCTION: Import and Establish Effective Natural Enemies

Procedure: Survey indigenous natural enemies.

Procedure: Participate in foreign exploration.

Procedure: Determine systematics and biogeography of pest and natural enemies.

Procedure: Cooperate in importation, quarantine and pre-release studies.

Procedure: Produce natural enemies through development of mass rearing technology.

Procedure: Release, establish and distribute natural enemies.

Procedure: Evaluate efficacy and study ecological/physiological basis for interactions.

FUNCTION: Conserve Natural Enemies to Increase Biological Control of Target Pests

Procedure: Identify potential predatory/prey and parasite/host associations; confirm identification of species involved in pest problem.

Procedure: Identify and assess factors potentially disruptive to biological control.

Procedure: Implement and evaluate habitat modification, horticultural practices and pest suppression tactics to conserve natural enemy activity.

FUNCTION: Augment Natural Enemies to Increase Biological Control

Procedure: Identify and study biological characteristics of candidate natural enemies (species and biotypes).

Procedure: Conduct experimental releases to assess feasibility.

Procedure: Develop methods for rearing, storing and release of natural enemies.

Procedure: Release natural enemies and assess their biological impact.

FUNCTION: Evaluate Environmental and Economic Impacts of Biological Control

Procedure: Evaluate the environmental impacts of biological control.

Procedure: Evaluate the economic impacts of biological control.

FUNCTION: Interact with clients and cooperators

Procedure: Develop and make presentations.

Procedure: Generate publications.

Procedure: Provide training and workshops.

  • Number of new projects initiated.
  • Number of new species deemed appropriate for introduction on an annual basis.
  • Number of organisms being reared per target species.
  • Number of collections made, training workshops convened, number of releases made by program and cooperator staff, percentage of releases that resulted in establishment.
  • Techniques developed for rearing, release and evaluations.
  • Number of completed study protocols, including data collection, analyses and interim and final reports including peer reviewed publications.
  • Reduction in pest population, density and impact.

Biological control projects are evaluated periodically by the program manager to determine the extent that they meet the intended mission.

Projects are reviewed and highlights forwarded weekly to the Branch Chief, and an annual summary is prepared for the PHPPS. Additionally, a professional annual report is produced and disseminated to colleagues and other interested persons.

Program activities are scrutinized by the program supervisor at regular intervals during staff meetings and all projects are thoroughly reviewed by the program supervisor at an annual meeting.

Core Values:

  • Work cooperatively among ourselves and with others.
  • Value biological control as an important component of pest management.
  • Be professional in science and service.

To be a recognized standard for biological control:

  • By increasing our level of participation and innovation in the introduction, establishment and use of natural enemies;
  • By establishing appropriate natural enemies leading to the successful control of pests in California's agricultural, urban, and natural systems.

To protect California's agricultural, natural and urban systems through the use of natural enemies.

Contact Us

Integrated Pest Control Branch
Biological Control Program
3294 Meadowview Road
Sacramento, CA 95832

Projects & Resources