Introduction of Nonindigenous Arthropod Pests of Animals

Abstract

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.

Current Limitations in the Control and Spread of Ticks that Affect Livestock: A Review

“…Early in 2007, during a small-scale survey of the ticks infesting cattle in the Ivory Coast, R. microplus was recorded for the first time in West Africa [67]. No R. annulatus or R. geigyi were recovered, although they had previously been recorded in this region.…”

“…The tropical bont tick arrived on cattle from Senegal in 1830 [66], and it is considered a severe potential threat to the cattle industry of the Americas because it is a vector of Ehrlichia ruminantium [67,68]. This tick has been considered a serious danger for the US cattle industry because it could spread from the Caribbean to the coasts of Florida.…”

Threat of Foreign Arthropod-Borne Pathogens to Livestock in the United States

“…There are a number of examples of exotic diseases or their potential vectors being intercepted before they could become established in U.S. livestock populations (Bram and George 2000). However, if circumstances are suitable for the propagation of a pathogen, it can be considered fortunate if an introduced disease is detected before it spreads.…”

“…An alarming variety of both natural and experimental vectors of heartwater, including A. hebraeum and A. variegatum, have been inadvertently introduced into the United States on wildlife imported from Africa and elsewhere during the last four decades (Bram and George 2000). Introductions of A. variegatum, A. hebraeum, A. marmoreum, and A. sparsum pose a high risk of being a source of heartwater.…”

“…There are also several arthropodborne diseases such as Venezuelan equine encephalitis, African swine fever, and bovine babesiosis, for which cooperation has been established with other countries. Although not considered an arthropodborne pathogen in the entomological sense, the eradication of the screwworm, Cochliomyia hominovorax (Coquerel), from North America, is a remarkable example of cooperation between neighboring countries to eliminate a major livestock parasite (Bram and George 2000).…”