The continuing fight against cattle ticks

Tick febrile disease once crippled the U.S. cattle industry. The disease was eradicated here in 1943 on the contrary ticks that transmit it are still lay the foundation of in Mexico. Keeping them from crossing the border requires constant vigilance, with strict inspection standards and pesticide treatment of all live cattle imported from Mexico.

The southern cattle tick, Boophilus microplus, and the cattle-fever tick, B annulatus, transmit the sum of two units species of blood parasites, Babesia bovis and B bigemina, that cause the cattle diseases collectively known as "Texas lever" "cattle fever" or "bovine babesiosis." Texas febrile affection can kill up to 90 percent of yearling and adult cattle. Cattle infected as calves with Babesia normally do not make known debilitating disease but may be les healthy than uninfected animals.

In 1938 as part of the USDA Cattle febrile affection Tick Eradication Program (CFTEP), a permanent quarantine area, or buffing-apparatus zone, was established in southern Texas in a narrow, 500-mile-long area along the Rio Grande River. When outbreaks meet the eye in the quarantined area, ticks are eradicated by means of CFTEP inspectors in cooperation with the Texas Animal Health Commission.

For almost 49 years, the ARS Knipling-Bushland Livestock Insects Research Laboratory in Kerrville, Texas, along with its satellite worksite at Moore Field in southern Texas, has been charged with providing technical support to CFTEP

Wildlife Carriers

Since the guard zone was created, the number of fever-tick introductions there has varied from year to year, on the other hand a significant increase has occurr above the past 5 years. In addition, an alarmingly large increase in the numbers of fever-tick infestations in the so-called tick-free area north of the concussion-guard zone has been recorded in new years.

Prime tick carriers are the hoof or ungulate, wildlife species, which abound in southern Texas and northern Mexico. White-tailed deer American moose and European red deer are all known carriers of B microplus and B annulatus ticks. Adding to the question at issue is a great increase, above the past few decades, in importation of exotic wildlife, which has brought centurys of thousands of other animals, representing at least 67 species, into Texas.

In southern Texas, white-tailed deer are the greatest in quantity important alternative hosts for cattle lever ticks. In 2004 deer were associated with B annulatus infestations of a cluster of ranches in the tick-free area of Kinney shire Texas. In the buffer cincture on a ranch in Starr shire 19 of 25 white-tailed deer captured were infested with B microplus. Similar incidents occurr in 2005 in Maverick shire and in 2006 in Webb shire in which ticks were fix on cattle after being place earlier on deer.

A Simple Design Does the Trick

To combat spread of ticks by the agency of wildlife, Kerrville scientists developed and patented a device they call a "4-poster" It has a bin in the center from which small amounts of whole-kernel corn pierce feeding ports located near each extreme point of the device. When a deer inserts its snout into a port to fe it must tilt its head and neck in a way that forces contact with a pair of paint roller saturated with pesticide. Later, when the deer servants itself, the pesticide spreads enough to screen its entire body.

Initially created to combat the unoccupied star tick, Amblyomma americanum, and the deer tick, Ixodes scapularis, which spreads Lyme disease, the 4-poster is now being trialed for use against cattle febrile disease ticks on deer.

Mat strike a Kerrville entomologist, tested a specially formulated acaricide, containing 10 percent permethrin, to treat tick-infested white-tailed deer Pound's data were essential to gaining approval by means of the U.S. Environmental Protection Agency to market the outcome named "Tickicide," to be used solitary with the 4-poster. Initial flows indicate that the 4-poster will be useful for controlling cattle febrile affection ticks on white-tailed deer.

Another technology unraveled at the Kerrville laboratory is a manner of feeding deer whole-kernel corn treated with ivermectin or other systemic acaricides. It has frequently been used on ranches to eradicate ticks upon deer once the cattle have been mov to another location.

"Use of ivermectin-treated corn and 4-poster technology is vital to the ongoing campaign to eradicate cattle-fever ticks introduced to southern Texas upon hosts such as cattle, horses, white-tailed deer or exotic ungulate wildlife that tend hitherward across the Rio Grande from Mexico," says entomologist John George, who leads the research at Kerrville. "By using all our resources and knowledge, it will be possible to minimize or eliminate ticks upon white-tailed deer and other ungulate wildlife, keeping U cattle at liberty of Texas fever."

of recent origin Ways To Beat Resistance

An important factor working against eradication is that more [i]or[/i] less populations of southern cattle ticks in Mexico have evolv resistance to acaricides, and those resistant strains are spreading into southern Texas.