Introduction of nonindigenous arthropod pests of animals

A variety of pathways exist for the introduction of nonindigenous insects, ticks, and mites of veterinary importance into the United States. The most prominent includes the natural migration of mosquitoes and flies by the fli ght of adults, ectoparasites entering the country on wildlife transport hos ts, and accidental introductions on animals legally imported through United States Department of Agriculture (USDA) quarantine facilities. Examples of the establishment and subsequent eradication of exotic pests of livestock are presented to illustrate the critical role of the USDA in protecting Ame rican agriculture with particular emphasis on the southern cattle tick, Boo philus microplus (Canestrini), the cattle tick, B. annulatus (Say), and the screwworm, Cochliomyia hominivorax (Coquerel). Priority group rating of no nindigenous arthropod pests and disease vectors are discussed. Although the primary responsibility for preventing the introduction and establishment o f arthropods that affect livestock and poultry rests on the shoulders of US DA professionals, insect surveys by extension entomologists along with obse rvations by research specialists and producers are also important in detect ing exotic arthropod species. Animal health professionals from all sectors of the livestock and poultry industries may well be the first line of defen se from the introduction of nonindigenous arthropods and the diseases they transmit.