No abstract

There are many exotic animal pathogens throughout the world that, if introduced into the United States. could have a significant detrimental impact on the health of livestock, agricultural economy, the environment, and public health. Many of these pathogens are arthropod-borne and potential vectors are readily available in the United States. A number of these arthropod-borne pathogens are discussed here as examples that illustrate the potential risk and the consequences of inadvertent introductions. Several International agencies have a role in global surveillance and in controlling animal diseases should they begin to expand their range. The risk to the United States is considerable. We propose that the United States invest in the improved infrastructure needed to reduce the risk of foreign arthropod-borne pathogens. Current U.S. programs focus on the exclusion of pathogens through regulation of animal movements and products, surveillance, especially trained animal disease diagnosticians, research support, international cooperation and, should pathogens enter our country, the resources for their prompt eradication. We suggest that the United States needs to develop a comprehensive, updated strategic plan to assess all aspects of current and future requirements, objectives, and resources needed to protect its national interests.

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 flight of adults, ectoparasites entering the country on wildlife transport hosts, 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 American agriculture with particular emphasis on the southern cattle tick, Boophilus microplus (Canestrini), the cattle tick, B. annulatus (Say), and the screwworm, Cochliomyia hominivorax (Coquerel). Priority group rating of nonindigenous arthropod pests and disease vectors are discussed. Although the primary responsibility for preventing the introduction and establishment of arthropods that affect livestock and poultry rests on the shoulders of USDA professionals, insect surveys by extension entomologists along with observations by research specialists and producers are also important in detecting exotic arthropod species. Animal health professionals from all sectors of the livestock and poultry industries may well be the first line of defense from the introduction of nonindigenous arthropods and the diseases they transmit.

associate laterally into sheets and are not able to stack into microfibrils. When the brightener is removed by washing, the insoluble glucan chains collapse into fibrils (Pig. ID).