Regulatory Entomology (Insects)

Regulatory entomology is concerned with preventing the unwanted movement of insects and related invertebrates from areas where they occur to areas where they do not occur. Nonnative species have caused untold amounts of damage to our crops, homes, environments, and persons. Officials in regional, state, or national governments achieve this goal with a five-component prevention program of exclusion, detection, eradication, identification, and public awareness. Exclusion is the primary prevention level. It uses phytosanitary regulations, including quarantines and other legal actions, to prevent the introduction of the quarantine pests. Detection is the secondary prevention level, which uses visual surveys or traps to find infestations of quarantine pests that have penetrated the exclusion barriers. Identification provides the name of the invading organism and information about its biology. It also provides intelligence to assist exclusion and eradication activities. Eradication is the tertiary prevention level. Eradication is the elimination of populations of quarantine pests found by the detection program. Public awareness strives to make the citizens aware of the regulatory laws concerning the importation of quarantine pests and items and enlists their cooperation in making the prevention efforts successful. The components work together much like a ladder with exclusion, detection, and eradication being the rungs, which are held together by identification and public awareness. Working together, these components can prevent the unwanted immigration of quarantine pests.

PEST EXCLUSION

The basic premise of pest exclusion is that it is better to live without pests than to live with them. History provides numerous examples of nonnative species that have caused extensive damage when brought into new areas. Examples of invasive species that have caused damage in nonnative areas include the Formosan termite (Coptotermes for-mosanus) in Hawaii and Louisiana, gypsy moth (Lymantria dispar) in the eastern United States, opuntia cactus (Opuntia spp.) and rabbits (Oryctolagus cuniculus) in Australia, brown tree snake (Boiga irregula-ris) in the Pacific region, American cockroach (Periplaneta americana) throughout most of the world, and Colorado potato beetle (Leptinotarsa decemlineata) in Europe. Pest exclusion uses phytosanitary regulations, including quarantines and other legal actions, to prevent the immigration of quarantine pests. Quarantines prohibit the movement of the quarantine pest or plants or other items known to be infested or liable to be infested from crossing the quarantine boundaries.
Quarantines may identify specific organisms (e.g., San Jose scale, Quadraspidiotus perniciosus) or groups of organisms (e.g., fruit flies in the family Tephritidae). Pest insects attack human food, fiber, shelter, or persons; carry diseases of people or other organisms, including domestic livestock or native biota; or are pests of human or natural environments (Table I ).
Plants or other regulated articles are prohibited from crossing the quarantine boundaries unless they meet compliance procedures specified in the phytosanitary regulations that render them free of the

quarantine pest. Compliance agreements and permits are authorizations to move the prohibited items under conditions prescribed by the quarantine issuer. Quarantine compliance may be performed at origin, the preferred option, or at destination, which is the less preferred option. The compliance requirements vary from those designed to keep the pest out of the regulated items, such as growing nursery stock in insect-proof screenhouses or applying pesticide sprays while the plants are growing, to those designed to kill any pests associated with the regulated items prior to or during shipment, including fumigation, hot/cold treatments, or irradiation (Table II ).
Permits are also used to regulate the importation and holding of live insects for exhibit or research by insect zoos, butterfly houses, public or

private research facilities and universities, and private citizens. The regulations that allow the insects to be held safely are specified in the permit issued to the person or entity requesting permission to import or hold live insects that are subject to regulation. Another form of pest exclusion uses the continual release of sterile insects throughout an area of high risk of invasion by that pest to preclude establishment. These sterile insects mate with wild adults as they emerge, producing infertile eggs. This preventative release approach stops the invading pest from developing infestations that may require eradication. This preventative release approach is being used against the Mexican fruit fly (Anastrepha ludens) along the Mexico-California border and against the Mediterranean fruit fly (Ceratitis capitata) in the greater Los Angeles area of California, along the Peru-Chile border, and along the Mexico-Guatemala border.

PEST DETECTION

Pest detection programs serve two purposes: to ensure that a political entity is free of the quarantine pest(s) regulated by their phytosanitary regulations and to find infestations of quarantine pests that have penetrated the exclusion barrier. There are two basic forms of pest detection: traps and visual surveys. The use of traps has many advantages and traps are the preferred method of detection of insect pests. However, not all pests respond to traps or lures. For these pests visual surveys, with their own advantages and disadvantages, are used (Table III ).

Traps may be completely visual, such as yellow traps used to catch aphids and whiteflies, but most often they contain one or more chemicals attractive to the target species (Table IV). These chemical lures include sex pheromones, pheromone precursors, parapherom-ones (attractant not of botanical origin or a pheromone precursor that attracts males), food lures, chemicals of unknown action, and combinations of visual traps and lures.

Visual surveys can look for the pest itself, such as the white garden snail (Theba pisana); the damage the pest can cause, such as that caused by the Asian longhorn beetle (Anoplophora glabripennis); or the abode of the pest, such as the galls of the balsam gall midge (Paradiplosis tumifex). Visual surveys may use food lures to attract and hold the pest as is done with the red imported fire ant (Solenopsis invicta).
Detection efforts are concentrated in those areas where the target pest might enter and where the pest may become established. In general, large urban areas have a greater number of invading exotic species than rural or agricultural areas. This is the result of people directly bringing in exotic invertebrates in the fruit, flowers, and other items that they obtain while traveling and the importation of large volumes of goods (food, plants, etc.) that are needed to service large population centers (Table V ).
If a pest is found during a detection program, a delimitation survey is used to determine whether an infestation exists and if so, its physical boundaries. Unlike detection efforts that try to uniformly cover an area, delimitation efforts strongly target the area immediately around where the pest was found, with decreasing effort as one moves away from that point. For example, Mediterranean fruit fly detection in urban areas of California deploys a uniform 4 Jackson traps baited with

Trimedlure per square kilometer. For delimitation, 100 Trimedlure-baited Jackson traps are deployed in the 2.56 km2 area (core area) centered on the site where the first fly was found. An additional 50, 25, and 20 Trimedlure-baited Jackson traps per 2.56 km2 are deployed respectively in three 1.6-km-wide rings around the core area.
Delimitation surveys are conducted until an infestation is confirmed and a decision about further actions is made or until it is determined that no infestation exists. The latter requires that no more target insects be found for a time period equal to several generations, typically two to three, of the pest. At the end of the delimitation effort, a trapping or visual survey program resumes at the detection level.
Delimitation efforts using visual surveys follow the same format, with a greater effort expended in the area immediately around the site where the pest was detected and diminishing effort as one moves away from that point.

PEST IDENTIFICATION

An important part of any detection program is the rapid and accurate identification of organisms that are found. Professional scientists provide these identifications and background information on the biology of the organism, which are used to help decide what, if any actions, may be taken against the pest. These professionals also provide information used to develop phytosanitary regulations and quarantine pest detection and delimitation programs.

PEST ERADICATION

Eradication of infestations of exotic pests is the most controversial aspect of regulatory entomology. Eradication is designed to eliminate a pest from a proscribed area, usually within a given time. Eradication programs are conducted at the point where the pest is found, not necessarily where it may do the most damage. Eradication programs using pesticide sprays in urban settings often generate considerable public outcry and opposition. Programs using nonpesticidal tactics or less intrusive methods of pesticidal applications engender little to no public concern. Thus the aerial application of pesticides or the extensive use of ground applications of pesticides in urban areas is strongly contested by the public, whereas mass trapping or male annihilation programs in the same areas are ignored. In general, successful eradication programs have the following components: the organism poses a clear-cut threat, an effective detection technique is available—usually not only visual surveys, the organism is limited in its distribution in the newly invaded area, continuous natural invasion of the organism cannot occur, and

a One or more tactics are often used against a pest.
effective techniques exist to reduce the target population below the point at which reproduction can occur (Table VI ).
Eradication procedures are applied to the target population for several life cycles of the organism beyond the last individual found. Posttreatment monitoring at delimitation levels is conducted for at least one additional life cycle of the pest. If no further individuals of the target organism are found within the treated area, eradication is considered to have been successful.

PUBLIC OUTREACH

Public outreach is conducted in a number of venues. Among the most frequently encountered are the forms that are required to be filled out before leaving a plane that has landed at a foreign airport or crossing a border. Information flyers handed out during eradication programs, on cruise ships, and at other sites are another venue through which the public is made aware of the exclusion efforts conducted on their behalf. Regular inspections of products moving into or out of an area keep professional importers and exporters aware of the quarantine regulations of their trading partners.
The five-component pest exclusion program described earlier, with modifications for local weather, topography, target species, and so on, is used by all countries that adhere to the International Standards for Phytosanitary Standards published by the Food and Agriculture Organization of the United Nations.