Landscape ecology of Rhipicephalus (Boophilus) microplus (Canestrini) (Ixodida: Ixodidae) outbreaks in the South Texas Coastal Plain wildlife corridor including man-made barriers

Authors: Showler, Allan; Perez De Leon, Adalberto - Beto

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2020
Publication Date: 4/27/2020
Citation: Showler, A., Perez De Leon, A.A. 2020. Landscape ecology of Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) outbreaks in the South Texas Coastal Plain wildlife corridor including man-made barriers. Environmental Entomology. 49(3):546-552. https://doi.org/10.1093/ee/nvaa038.
DOI: https://doi.org/10.1093/ee/nvaa038

Interpretive Summary: Landscape features and the ecology of hosts influence the distribution of invasive tick species. The southern cattle fever tick transmits causal agents of babesiosis in cattle and it infests exotic, feral nilgai and indigenous white-tailed deer on the South Texas coastal plain wildlife corridor. The corridor extends from the Mexico border to cattle ranches extending north from inside Willacy Co. Outbreaks of the southern cattle fever tick infesting cattle and nondomesticated ungulate hosts since 2014 on the wildlife corridor have focused attention on host infestation management and dispersal. However, there is a knowledge gap on the ecology of southern cattle fever tick outbreaks on the South Texas coastal plain wildlife corridor. Ixodid distribution on the wildlife corridor is strongly influenced by habitat salinity. Saline habitats, which constitute '25 percent of the wildlife corridor, harbor few ixodids because of occasional salt toxicity from hypersaline wind tides and infrequent storm surges, and from efficient egg predation by mud flat fiddler crabs. Southern cattle fever tick infestations on nilgai were more prevalent in part of the corridor with mixed low salinity and saline areas than in an area that is more extensively saline. The different levels of infestation suggest that man-made barriers have created isolated areas where the ecology of southern cattle fever tick outbreaks involve infested nilgai. The possible utility of man-made barriers for southern cattle fever tick eradication in the lower part of the South Texas coastal plain wildlife corridor is discussed.

Technical Abstract: Landscape features and the ecology of suitable hosts influence the phenology of invasive tick species. The southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini) (Ixodida: Ixodidae), vectors causal agents of babesiosis in cattle and it infests exotic, feral nilgai, Bosephalus tragocamelus Pallas, and indigenous white-tailed deer, Odocoilus virginianus (Zimmerman), on the South Texas coastal plain wildlife corridor. The corridor extends from the Mexico border to cattle ranches extending north from inside Willacy Co. Outbreaks of R. microplus infesting cattle and nondomesticated ungulate hosts since 2014 on the wildlife corridor have focused attention on host infestation management and, by extension, dispersal. However, there is a knowledge gap on the ecology of R. microplus outbreaks on the South Texas coastal plain wildlife corridor. Ixodid distribution on the wildlife corridor is strongly influenced by habitat salinity. Saline habitats, which constitute '25 percent of the wildlife corridor, harbor few ixodids because of occasional salt toxicity from hypersaline wind tides and infrequent storm surges, and from efficient egg predation by mud flat fiddler crabs, Uca rapax (Smith). Rhipicephalus microplus infestations on nilgai were more prevalent in part of the corridor with mixed low salinity and saline areas than in an area that is more extensively saline. The different levels of R. microplus infestation suggest that man-made barriers have created isolated areas where the ecology of R. microplus outbreaks involve infested nilgai. The possible utility of man-made barriers for R. microplus eradication in the lower part of the South Texas coastal plain wildlife corridor is discussed.