Comparison of natural and artificial odor lures for nilgai (Boselaphus tragocamelus) and white-tailed deer (Odocoileus virginianus) in South Texas: developing treatment for cattle fever tick eradication

Authors: Goolsby, John; SINGH, NIRBHAY - Guru Angad Dev Veterinary & Animal Sciences University; ORTEGA-S, ALFONSO - East Foundation; HEWITT, DAVID - Non ARS Employee; CAMPBELL, TYLER - East Foundation; WESTER, DAVID - Texas A&M University; Perez De Leon, Adalberto - Beto

Submitted to: International Journal for Parasitology: Parasites and Wildlife
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2017
Publication Date: 8/1/2017
Citation: Goolsby, J., Singh, N., Ortega-S, A., Hewitt, D.G., Campbell, T., Wester, D., Perez De Leon, A.A. 2017. Comparison of natural and artificial odor lures for nilgai (Boselaphus tragocamelus) and white-tailed deer (Odocoileus virginianus) in South Texas: developing treatment for cattle fever tick eradication. International Journal for Parasitology: Parasites and Wildlife. 6:100-107.

Interpretive Summary: Cattle fever ticks (CFT) Rhipicephalus (=Boophilus) microplus and Rhipicephalus annulatus are invasive livestock pests that are endemic to Mexico and invasive along the Texas – Mexico border. Acaricide resistance, alternate wildlife hosts, and pathogenic landscape forming weeds present challenges for sustainable eradication of this pest in the U.S. CFT are the biological vectors of the infectious agents causing bovine babesiosis, which kills cattle and severely affects the profitability of the livestock industry. Efforts to eradicate CFT from the United States have been successful; however, a quarantine area is maintained in south Texas between the U.S. and Mexico to prevent re-infestation from neighboring Mexico states where CFT are established as wildlife and stray cattle that carry CFT can freely cross the border. In recent years, there has been an increase in CFT infestations outside of the quarantine area in south Texas. Nilgai (Boselaphus tragocamelus), an exotic Asian antelope widely distributed in southeastern Texas, carry CFT and spread CFT through the landscape. Odor lures were tested to develop a treatment method for CFT-infested nilgai. Field dressings (offal) of nilgai were more attractive than the other artificial lures tested including screwworm lure (which mimics offal), bovine intestinal fluids, and citronella oil. However, we did document development of nilgai latrines at screwworm lure sites, which may mean this lure should be further investigated. A lure and treatment method for nilgai is needed to support the cattle fever tick eradication program in south Texas. The lure technology could reduce the need for harvesting nilgai in CFT infested pastures.

Technical Abstract: Cattle fever ticks (CFT), vectors of bovine babesiosis and anaplasmosis, were eradicated from the United States by 1943, but are frequently reintroduced from neighboring border states of Mexico via stray cattle and wildlife hosts including white-tailed deer (Odocoileus virginianus) (WTD) and nilgai antelope (Boselaphus tragocamelus). Nilgai antelope are exotic bovids from India that are hosts of CFT, have large home ranges as compared to WTD, and thus have the potential to spread CFT through the landscape. Currently, there are no methods to control CFT on nilgai. Odor lures were evaluated to determine if nilgai could be attracted to a central point for development of control methods. Four treatments were included in the study. Nilgai offal, a natural odor lure used as the positive control, was compared to three artificial odors: screw worm lure, volatile fatty acids, and citronella oil. Studies were conducted on a free-ranging population of nilgai at the East Foundation's Santa Rosa Ranch (Kenedy Co., near Riviera, Texas, USA). Game cameras were used to document visitation to the lures. In the ten randomly placed transects, 110 nilgai and 104 WTD were photographed. Offal had significantly more visits by nilgai (71% of total visits) than screwworm (15%), VFA (11%), and citronella (4%). For WTD, there was no significant difference in visitation at the lure treatments.