Rhipicephalus annulatus (formerly Boophilus annulatus) is a hard tick found most often on cattle. Heavy tick burdens on animals can decrease production and damage hides. R. annulatus can also transmit babesiosis (caused by the protozoal parasites Babesia bigemina and Babesia bovis) and anaplasmosis (caused by Anaplasma marginale).

Babesiosis or “cattle fever” was eradicated from the United States between 1906 and 1943, by eliminating its vectors R. annulatus and Rhipicephalus microplus. Before its eradication, babesiosis cost the U.S. an estimated $130.5 million in direct and indirect annual losses; in current dollars, the equivalent would be $3 billion. R. annulatus and R. microplus still exist in Mexico, and a permanent quarantine zone is maintained along the Mexican border to prevent their reintroduction into the U.S. Within this zone, the USDA’s Animal and Plant Health Inspection Service (APHIS) conducts a surveillance program to identify and treat animals infested with these exotic ticks. Recently, increased numbers of infestations have been recorded in the quarantine zone.