Exotic & Invasive Pests
Exotic plant pest species are those that are not established within the United States. The definition is sometimes expanded to include invasive species or species that may have become "biologically established" and are being managed in an eradication, containment, or other program. Invasive species are not native to the ecosystem under consideration and their introduction may cause economic or environmental harm, or harm to human health.
A significant portion of agricultural losses in the United States are caused by non-native species of insects, mites, weeds, plant pathogens, nematodes, or other pests. This is largely because many crop plants in the United States are of foreign origin. It is easy for pest species to be introduced with the crops and to become established. Foreign pest species have frequently been introduced and established in new areas where plant hosts exist. Without natural control agents from their native environs, pests can develop large populations and become economically damaging.
Thousands of foreign species are potential agricultural or environmental pests in the United States. Current ability to predict potential damage, host range, and geographical distribution of the vast number of foreign plant pests is limited. It is impossible to survey for all potential exotic pests considering the large number of known pests, the diversity of crops and ecosystems, the huge geographic area involved, and the difficulties of prediction. Pest detection surveys must be limited to directed surveys for pests that have a higher probability of introduction and establishment into specific areas, for pests on specific commodities, or for exotic plant pests which are found during a survey for another pest.
