Environmental Assessment Favorable for Fever tick Eradication

Wildlife can serve as carriers for cattle fever ticks, which could spread to surrounding ranches. ( USDA )

Animal-health officials move one step closer to enacting an eradication plan with a positive environmental-assessment report.

Cattle fever ticks, formerly eradicated from the United States, have made a comeback in southeastern Texas, particularly in the Laguna Atacosa and Lower Rio Grande Valley National Wildlife Refuges.

The cattle fever tick (Rhipicephalus annulatus and R. microplus) carry and transmit Babesia bovis or B. bigemina, protozoa pathogens that invade and destroy red blood cells ultimately resulting in an 80 to 90% mortality rate among susceptible naive cattle. The ticks and associated cattle disease were widespread across much of the Southeast, but efforts from USDA/APHIS and state animal-health agencies eradicated them from the United States in the 1940s. The USDA also established a 500-mile quarantine zone along the Rio Grande River to keep the ticks from re-establishing.

In recent years though, cattle fever ticks have moved into the area outside the permanent quarantine zone, primarily on wildlife carriers such as whitetail deer and nilgai antelope. In response, USDA and the U.S. Fish and Wildlife Service developed an eradication plan focusing primarily on the two wildlife refuges. Recommendations in the plan include prescribed burns, reductions in wildlife populations, using ivermectin-treated corn to treat wildlife for tick infestations and grazing cattle on the refuges, as a means of monitoring tick populations and as a way to attract and kill ticks, since cattle are the preferred host. Read more about that plan in “Fever Tick Proposal Includes Grazing Wildlife Refuges.”

Recently, the USDA and the U.S. Fish and Wildlife Service issued their Finding of No Significant Impacts (FONSI) for an environmental assessment (EA) for the eradication plan. Based on the analyses in the EA and input from the public, the agencies concluded that implementing the preferred action alternative would not have a significant impact on the quality of the human environment.

Read the full environmental assessment report.