National Plant Board
Plant Quarantine, Nursery Inspection, and Certification Guidelines
Elements of Pest Prevention
A pest prevention program consists of five major elements. This appendix identifies and briefly describes those elements.
I. Pest Exclusion – The goal of pest exclusion is to keep exotic pests out of the area of concern. Pest pathways must be identified and evaluated as to their potential as avenues of entry. The basic modes of pest spread or dispersal are natural and artificial. Artificial pathways are the major focus of pest exclusion efforts and are distinguished from natural pathways which regulatory agencies cannot control using traditional pest risk mitigation measures. As examples, lack of control over natural spread is evidenced in the fact that winged insects and pathogenic propagules often can be spread great distances on wind currents; and soil borne pests can be transported over long distances in water. While natural barriers such as oceans, deserts, and mountain ranges impede natural spread and facilitate pest exclusion efforts, natural spread is generally accepted as being beyond control especially when there is a continuum of hosts and natural modes of movement exist.
The best strategy for dealing with natural spread is a regional one that focuses on keeping exotic pests out of large geographic areas or establishing pest-free areas via quarantine, detection, and eradication programs. These strategies require close cooperation and coordination among all those governmental agencies within the geographic area of concern. For example, keeping the Mediterranean fruit fly out of the continental United States requires the cooperation of federal, state, and local governments. Optimally, it also requires the cooperation and support of the Canadian and Mexican governments; and governmental efforts must have support from the regional and the National Plant Boards, industry and the public. In North America, the North American Plant Protection Organization (NAPPO) is responsible for harmonizing the pest prevention systems of its three member nations: Canada, Mexico, and the United States. The North American Free Trade Agreement identifies the NAPPO as one the organizations responsible for dealing with international quarantine issues.
The basic artificial pathways are aircraft, buses, ships, trains, trucks, and automobiles. Each of these pathways serve as conduits in a number of ways: commercial, military, and public transport of infested commodities; hitchhiking pests; and smuggling. Aircraft operations include cargo (domestic and foreign mail, private parcel carriers, commercial airlines), passenger (charter and commercial), private, and military. Ship operations likewise include cargo, passenger (or cruise ships), private yachts, and military. Bus, train, automobile, and truck operations are narrower, but their high numbers and frequency of international and interstate movement keep them high on the list as significant pest pathways. Consequently, international airports, harbors, and land ports of entry; and foreign mail centers are key inspection points for foreign pest exclusion. Within the United States, airports; bus, express package carrier, truck and train terminals; U.S. Postal Service sectional centers; highway border agricultural inspection stations; and terminal arrival points such as nurseries, grain mills, wholesale pet stores, etc. are the principal points for state-operated domestic pest exclusion inspection activities.
As smuggling operations are a growing concern, states may wish to establish an investigation team to perform undercover operations and gather facts needed for successful prosecution of violations.
II. Pest Detection – Even the best pest exclusion system is not perfect. Pests still penetrate the pest exclusion barrier and get established. The goal of pest detection is to discover infestations while they are still small enough to eliminate. Various systematic and periodic visual surveys and annual detection trapping programs are conducted to accomplish this end.
Once an exotic pest is found, additional visual survey or trapping is performed to determine if an infestation exists; and, if so, how extensive it is. The latter survey is referred to as a delimitation survey and is a prerequisite for determining the feasibility of eradication. It also is needed to identify the areas where eradicative treatments and quarantine measures need to be applied.
Formal detection survey and trapping are complemented by the support of university researchers and extension agents, pest control advisors and operators, farmers, and the public in the form of reporting unusual pests, diseases, and abnormalities discovered in the normal course of their business or private activities.
III. Eradication – Eradication involves the application of appropriate treatments and quarantine measures followed by post-treatment visual survey, or trapping, or other monitoring to determine if eradication has been accomplished. Typically, eradication is defined by negative survey or trapping for one or two full seasons or life cycles after the termination of eradication treatments. Ultimately, it is determined between trading partners.
IV. Pest Diagnostics and Record-Keeping – The foundation of an effective pest prevention program is the ability to provide timely and accurate pest diagnostics for specimens and samples collected in the performance of the exclusion and detection work. Record-keeping is a critical adjunct in that exclusion interception and detection records are essential for making valid and meaningful pest pathway studies, risk analyses, and quarantine evaluations.
V. Public Information and Education – Effective pest prevention programs require an educated and supportive public. People must know what quarantine restrictions exist and why they exist in order to be motivated to comply with them and to support funding for them. Unfortunately, this element of pest prevention is the least funded and most neglected. More emphasis must be placed on it in the future because international commerce is rapidly increasing and more and more people are traveling to foreign locations for business and pleasure.