Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) larvae collected from vegetation in the coastal wildlife corridor of southern Texas and research solutions for integrated eradication

Authors: Osbrink, Weste; Showler, Allan; Abrigo, Veronica; Perez De Leon, Adalberto - Beto

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/24/2019
Publication Date: 12/24/2019
Citation: Osbrink, W.L., Showler, A., Abrigo, V., Perez De Leon, A.A. 2019. Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) larvae collected from vegetation in the coastal wildlife corridor of southern Texas and research solutions for integrated eradication. Journal of Medical Entomology. 57(4):1305–1309. https://doi.org/10.1093/jme/tjaa002.
DOI: https://doi.org/10.1093/jme/tjaa002

Interpretive Summary: Cattle fever ticks that remain established in Mexico are kept out of the United States through efforts of the Cattle Fever Tick Eradication Program. Previous research documented the potential for reinvasion of the United States by cattle fever ticks, which are vectors of the microbes causing bovine babesiosis, or cattle tick fever. Bovine babesiosis is a malaria-like disease deadly to cattle. Projections indicate the re-emergence of bovine babesiosis would kill many cattle and cost the national livestock industry billions of dollars. However, growing populations of white-tailed deer and nilgai, which are suitable wildlife fever tick hosts, make it challenging to keep the United States cattle fever tick-free. Deer and nilgai also inhabit portions of Cameron and Willacy Counties in south Texas comprising wildlife corridors. Continued research in support of the Program involves ecological investigations and the enhancement of surveillance approaches for cattle fever ticks. Here, we report the collection of free-living southern cattle fever tick, Rhipicephalus microplus, larvae by dragging flannel flags over vegetation in the wildlife corridors of Cameron and Willacy Counties. This record confirms a similar finding in Zapata County and highlights how factors related to global change pose challenges to eradication efforts that did not exist when the Program started operations in 1907. Current research on technologies that could be used for area-wide management of cattle fever tick larvae in south Texas and how this could be applied to integrated eradication efforts are discussed.

Technical Abstract: The potential for reinvasion of the United States by cattle fever ticks, Rhipicephalus (Boophilus) annulatus and R. microplus, which remain established in Mexico, threatens the viability of the domestic livestock industry because these ticks vector the causal agents (Babesia bovis and B. bigemina) of bovine babesiosis. The Cattle Fever Tick Eradication Program safeguards the health of the national cattle herd preventing the re-emergence of bovine babesiosis by keeping the United States cattle fever tick-free. Here, the collection of free-living southern cattle tick, R. microplus (Canestrini) (Ixodida: Ixodidae), larvae by sweeping flannel flags over vegetation in the wildlife corridor of Cameron and Willacy Counties, TX, is reported. Finding R. microplus larvae on vegetation complements reports of infestations in wildlife hosts inhabiting the southern Texas coastal plains. Land uses and environmental conditions have changed since cattle fever ticks were eradicated from the United States by 1943. These changes complicate efforts by the Cattle Fever Tick Eradication Program to keep cattle in the United States free of the cattle fever tick disease vectors. Current scientific research on technologies that could be used for area-wide management of fever tick larvae in south Texas and how this could be applied to integrated eradication efforts are discussed.