National Tick Surveillance Program 

 Calendar Year 1984 



During calendar year 1984, the collection and submission 

 of ticks from native and imported animals plus plant and 

 animal material was 29 percent less than in 1983. There 

 were 7,213 collections in 1984, 10,207 in 1983, 9,086 in 

 1982, 9,381 in 1981, 7,763 in 1980, and 11,553 in 1979. 



Interception of a Heartwater Vector in Texas 



In June 1984, Amblyomma hebraeum, a vector of heart- 

 water (Cowdria ruminantium), was collected from a female 

 black rhinoceros on a cattle ranch near Linn, Texas. This 

 rhino was one of three rhinos on the ranch. These three 

 rhinos were part of a consignment of five rhinos imported 

 into the United States from South Africa in March 1984. 

 The other two rhinos in the consignment were shipped to 

 an exotic game ranch near Glen Rose, Texas. The black 

 rhinoceroses, an endangered species, were brought to the 

 United States as part of an experimental breeding 

 program. 



The ticks were collected by Dr. Sherri L. Huntress, a 

 veterinarian from the Gladys Porter Zoo in Brownsville, 

 Texas. One of the female rhinos died unexpectedly and 

 during the postmortem examination, Dr. Huntress noticed 

 several "unusual" ticks which were collected and forward- 

 ed to the National Veterinary Services Laboratories, Ames, 

 Iowa, where they were identified as male specimens of A. 

 hebraeum, the South African bont tick. 



Because of possible exposure of cattle to the tick-infested 

 rhino, a State quarantine was placed on the ranch near 

 Linn, Texas. Since there were no cattle on the exotic 

 game ranch near Glen Rose, this ranch was not quarantin- 

 ed. A team of entomologists from Veterinary Services was 

 sent to Texas to inspect the rhinos for additional ticks and 

 to conduct a tick survey on both ranches. The en- 

 tomologists were assisted by experienced personnel from 

 Veterinary Services Fever Tick Eradication Program, 

 Laredo, Texas. 



Examination of the rhinos by the entomologists and tick 

 eradication specialists on the ranch near Linn revealed ad- 

 ditional male specimens of A. hebraeum as well as native 

 ticks (Amblyomma cajennense). No A. hebraeum were 

 found on the rhinos at the Glen Rose ranch; however, 

 another native species, Amblyomma americanum, was 

 found on the two rhinos. Surveys of the pastures on both 

 ranches were negative for A. hebraeum. 



After examination, the rhinos on both ranches were 

 thoroughly sprayed with 0.125 percent coumaphos. The 

 pasture used by the rhinos at the ranch near Linn was 

 sprayed with 0.25 percent chlorpyrifos. A followup in- 

 vestigation was conducted on both ranches a month after 

 the first investigation and no further evidence of A. 



hebraeum was found. In addition, wildlife and livestock on 

 the ranch near Linn were periodically sampled throughout 

 1984 for ticks by Veterinary Services tick eradication 

 specialists. No A. hebraeum were found on any of the 

 animals examined. 



The impact of the interception of A. hebraeum was 

 minimized by three factors: 1) the results of the investiga- 

 tion indicated that only male A. hebraeum were 

 transported from Africa; 2) rhinos are nonruminants and 

 are therefore not susceptible to heartwater; and 3) the 

 rhinos came from an area in South Africa reportedly free 

 of heartwater. 



There are two principal avenues by which foreign animal 

 diseases may enter the United States: 1) importation of 

 diseased animals or 2) importation of foreign animal 

 disease vectors. These risks are greatly reduced when 

 dealing with wild or domestic animals for which the U.S. 

 Department of Agriculture has jurisdiction. However, rhinos 

 and some other nonruminants are not presently regulated 

 by the U.S. Department of Agriculture. Thus, rhinos, 

 elephants, large cats, and various other classes of non- 

 domesticated animals may presently enter the United 

 States without being inspected for parasites or diseases. 

 The increasing volume and rapidity of commerce via air 

 transport have intensified the danger of the introduction 

 and establishment of exotic vectors. This is particularly 

 true with the recent trend towards placing zoological 

 animals in "natural-type" environments that directly ex- 

 pose susceptible domestic livestock and native wildlife. Im- 

 porters of zoological animals, State, and Federal 

 regulatory personnel should be aware of this danger and 

 take necessary precautions to prevent the introduction and 

 establishment of exotic parasites and diseases. 



Boophilus microplus in Puerto Rico 



The cooperative eradication program between the U.S. 

 Department of Agriculture and the Commonwealth of Puer- 

 to Rico Department of Agriculture to eliminate B. microplus 

 gained momentum in 1984. The program continued the 

 systematic treatment of infested herds from two head- 

 quarters, one on the eastern and the other on the western 

 end of the island. The eastern headquarters is located at 

 Juncos; the western headquarters is at Arecibo. During 

 1984 there were some 1,279 herds comprising over 42,000 

 animals under treatment and supervision by the Juncos 

 station. There are 3,501 total premises in the Juncos 

 quarantine area. The Arecibo quarantine area has 4,004 

 premises and during 1984 over 1,500 herds with more 

 than 17,000 animals were under treatment. 



The total tick eradication budget for 1984, which included 

 funds from the USDA, APHIS; the Commonwealth; and 



