Submitted to: United States Animal Health Association Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/1996
Publication Date: N/A
Interpretive Summary: Two species of cattle fever ticks, the southern cattle tick and the cattle tick, were eradicated from the U.S., but are widespread in Mexico. Outbreaks of cattle fever ticks occur frequently in south Texas where ticks are transported across the Rio Grande River on wildlife, stray livestock, or livestock which are moved illicitly from Mexico. The Fever Tick Eradication Program (FTEP) of APHIS, VS is responsible for maintaining a quarantine and eradicating outbreaks of cattle fever ticks to keep these vectors of the agents of cattle fever from becoming reestablished in the southern U.S. ARS is developing technology to resolve three technological issues of the FTEP: 1) how to prevent the dissemination of pesticide resistant southern cattle ticks from Mexico into the southern U.S.; 2) how to insure that effective pesticides are available to the eradication program; and 3) how to eradicate cattle fever ticks when white-tailed deer rand other secondary hosts are involved? ARS is perfecting traditional approaches and developing sensitive molecular methods to detect pesticide resistance in tick populations. Problems related to the management and disposal of coumaphos in dipping vats have been resolved, and alternatives to coumaphos such as amitraz have been tested. A new method that uses ivermectin-treated corn has been invented for controlling ticks on white-tailed deer and related exotic game animals.
Technical Abstract: Several technological questions must be resolved by ARS to insure the ability of APHIS, VS to protect the southern U.S. against the southern cattle tick and the cattle tick: 1) how to prevent the spread of pesticide resistant southern cattle ticks from Mexico into the southern U.S.; 2) how to insure that effective pesticides are available to the eradication program; and 3) how to eradicate cattle fever ticks when white-tailed deer and other secondary hosts are involved? Research to protect the U.S. against resistant cattle fever ticks is focusing on the improved application of current discriminating dose tests and the development of molecular probes that could detect the occurrence of resistance genes in low frequencies and provide results in a few days instead of one or two months. To preserve the useful life of coumaphos research has been done to test a technique that assures the stability of the product in dipping vats. .Also, a method was developed for destroying coumaphos in spent vat fluids to permit safe disposal of the liquid waste. Alternatives to coumaphos such as amitraz have been tested to determine efficacy and manageability in dipping vats under eradication program conditions. To provide the means for eradicating cattle fever ticks when white-tailed deer or other ungulate wildlife are complicating factors, technology such as ivermectin-treated corn has been developed.