Frequently Asked Questions (FAQ)
What is a non-indigenous organism? An organism that occurs in an area outside its native range. It may have been moved to the new area intentionally, accidentally or on its own. The words ‘exotic’ and ‘alien’ are often used interchangeably with non-indigenous. Many non-indigenous organisms are highly beneficial in the area of introduction. For example, some of our most important crops are non-indigenous (e.g. citrus, sugarcane, corn, cotton), as well as several beneficial insects (honey bees, many introduced biological control agents). However, a few exotic organisms become agricultural pests or invade and cause damage to natural ecosystems.
What is a naturalized organism? A non-indigenous organism that is permanently established and is self-sustaining in a non-native area. Botanists use the term naturalized when referring to plants, whereas biological control workers typically refer to biological control agents as ‘established’ once the agent has become a permanent member of an area’s fauna. In an ecological sense, naturalized and established mean the same thing. Brazilian peppertree and melaleuca are two examples of the many naturalized plants in Florida.
What is an adventive insect? An adventive insect has recently arrived in a new geographic area and established a viable population.
What is an invasive organism? An alien organism that is naturalized and disrupts naturally occurring native communities.
Why are we concerned about exotic invasive organisms? The invasion of exotic organisms into the United States is estimated to cost $138 billion annually. Exotic invasive organisms cause direct damage in agriculture, and may invade natural areas displacing native species and disrupting ecological processes.
What is classical biological control? Exotic organisms often reach higher densities in their adopted homes than in the native homes due to a lack of suppression from natural enemies (parasitoids, predators, pathogens in the case of insects and herbivorous arthropods and pathogens for plants). Classical biological control strives to reunite invasive pests with their natural enemies by identifying and introducing the natural enemies into the area of invasion. The natural enemies are introduced through quarantine and if deemed safe, are eventually released into the new environment. Ideally, the natural enemy will become permanently established and provide a self-sustaining control of the exotic pest. Other types of biological control include augmentation and conservation. Augmentation involves mass rearing and release of native or exotic biological control agents, and is not expected to provide a permanent solution to a pest problem. Conservation is using sound agronomic practices to protect or enhance natural enemy populations already existing in the envirnonment.
Why do we invest in classical biological control? The initial cost of a biological control program is often large, and includes investments in facilities, personnel, travel to foreign countries, funds for foreign exploration for natural enemies, host range studies in quarantine, mass production, release, and evaluation. However, once a natural enemy is established, the benefits continue to accrue into the foreseeable future, with no further costs. In contrast, control using other methods, such as pesticides, never ends.
How do invasive organisms arrive in new areas? The majority of invasive organisms that arrive in Florida are aided in their transport by man. Most invasive plants were introduced intentionally through the aquarium trade and the ornamental horticulture industry. Insect invaders are most often unintentionally introduced as hitchhikers on agricultural commodities and packing materials. A very few organisms may find their own way into Florida, but this is a very rare occurrence.
How do we ensure that biological control organisms will not cause problems once released in Florida? Biological control agents are carefully selected based on their host specificity. The primary objective is to introduce natural enemies that will attack only the target pests. Information on host specificity is obtained from scientific literature, and from studies conducted in the native home of the natural enemy. Additionally, knowledge of the taxonomy of the natural enemies is often informative as some taxonomic groups are known to be more host specific than others. Once putative host specific natural enemies are introduced, they undergo further study in a quarantine facility, such as the one in Fort Pierce. With insect biological control agents, the primary purpose of quarantine is to ensure that the natural enemy is free from its natural enemies (hyperparasitoids, pathogens) which may impede its establishment and lower its impact. For plant biological control agents, extensive non-target studies are conducted on native plants which are related to the target and on plants of agricultural importance. Once a sufficient amount of data has been gathered on a weed biological control agent, a petition for release is prepared and submitted to the Technical Advisory Group (TAG) of USDA/APHIS for approval.
How soon can results from a classical biological program be seen? There is no set answer to this question. The process of identifying the native home of the pest, finding host specific natural enemies, introducing these in quarantine, developing rearing methods and conducting host range studies can take years, and this is even before the agent is released in the field. Once released, populations of biological control agents may go through a long lag period before exponential population growth allows the agent to begin controlling the pest. The lag period can last several years. Classical biological control of invasive plants usually takes longer than biological control of insects because of the requirement to test the agent against a wide range of potential non-target plants prior to receiving permission to release. In short, the amount of time required can be from less than one year to as much as 20 years.
Last Edited: 05/19/2005