CORE ers Poe 


5-year 5-year 
average average 



Activities 

Number Number Number Number Number Number Number Number 
Exposures to clean premises .... 108 26 33 16 46 26 136 91 
Re-exposures to held premises .. 73 3 2 1 1 8 8 6 

U.S. livestock straying into 
Mexico and returning 
Caught et aereast- teiey-)atetyoroien ick 7 16 31 16 13 28 20 39 
Importation of livestock from 
tick-infested areas of Mexico 
into Texas 
Offered fonimportation’=..5 5.54. eee Roi Ree iayateamiaderohasoon pera choke close eae 692,665 671,824 503,817 819,210 
Rejected because of B. spp. infestation ...................20.. 11,707 13,289 24,327 9,936 58,328 
1 The systematic area is that area under Federal quarantine; the final area is that area outside the area under Federal quarantine. 
2 8,271 cattle and 24,909 horses were sprayed (rather than dipped). All treatments were with arsenic except as indicated on 
page 2. 
3 Herds held for further treatment include all herds whether infestation was in all cattle in herds or confined to Mexican strays. 
All cattle involved in these herds are native cattle. 
22 herds of 35 head of tick-infested Mexico livestock were found, all in the systematic area. 
Cattle offered for importation from Mexico are carefully inspected for ticks when presented 
for entry. They must be free of ticks and must be given a precautionary dipping before entering the 
United States. 
Eleven dipping vats met the criteria required for use of organophosphorous dips. In these vats, 
840 cattle and 416 horses were dipped with dioxathion (Delnav) permitted dip; also 1,066 cattle 
and 10,217 horses were sprayed with dioxathion. In two of these vats, 5,340 cattle and 159 horses 
were dipped in coumaphos (Co-Ral); one horse was sprayed with coumaphos. Seventy-four dipping 
vats met the criteria required for use of arsenic; and 107,667 cattle and 5,535 horses were dipped in 
arsenic. Also, 7,205 cattle and 14,691 horses were sprayed with arsenic. 
U.S. Virgin Islands and Guam 
The U.S. Virgin Islands of St. Croix, St. Thomas, and St. John remain tick-infested and under 
Federal quarantine. The Island of Guam is also under Federal quarantine. 
Ticks collected from cattle on St. Croix were identified on September 1, 1967, as Amb/yomma 
variegatum (tropical bont tick): This was the first evidence that the tropical bont tick might 
establish itself on U.S. territory. This tick is an important pest in many areas of the world and can 
serve as a vector of diseases affecting animals and man. The tick is a three-host tick with a very 
broad host range. Generally, the adult tick feeds on larger animals; and the larval and nymphal 
stages feed on smaller animals such as cane rats, ground squirrels, and mongooses. 
