USDA Releasing Sterile Cattle Ticks on Virgin Islands
Apr. 06, 1988
WASHINGTON (AP) _ Millions of sterile male cattle ticks will be released on one of the U.S. Virgin Islands to test whether the procedure can be used to control cattle fever, the Agriculture Department said Wednesday.
''We hope sterile (male) releases will stop female ticks from producing new generations that would infest cattle,'' said Ronald B. Davey, an entomologist in the department's Agricultural Research Service. ''Island people are safe from the disease. Humans are not bitten by the tick, nor do they get the disease.''
Cattle fever, or babesiosis, kills up to 80 percent of the adult cattle that get the disease, he said.
The experiment will be tried for the first time late this year on St. Croix. Cattle fever is widespread in the Caribbean, including the U.S. Virgin Islands and Puerto Rico, as well as in Mexico and many other areas, he said.
Davey, who works at the agency's Cattle Tick Fever Research Laboratory, Mission, Texas, said cattle become anemic after the ticks bite them, injecting a protozoan parasite into the bloodstream.
Cattle ticks ''periodically sneak over the Mexican border into Texas'' where a USDA eradication program stops them from spreading beyond a buffer zone, he said.
''These ticks are tough,'' Davey said in a statement issued here. ''If they were to get a strong hold again in the southern United States, the disease could devastate the southern cattle industry. All U.S. cattle breeds are susceptible.''
The sterile male ticks are hybrids, which produce no offspring when they mate. Davey said the test will be on 130 wooded acres USDA has leased from the Virgin Islands government.
No cattle are in the area now, so Davey expects there are few ticks. As part of the preparation, however, cattle will be put into the wooded area along with some naturally fertile ticks. After those ticks settle in, their numbers will be estimated.
Then, Davey explained, about five hybrid ticks for each estimated natural tick will be released at two-month intervals.
Until a count is made of the natural ticks, no estimate is available of how many sterile hybrids will be released, but the number could be in the hundreds of millions or even billions.