Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) Larvae Collected From Vegetation in the Coastal Wildlife Corridor of Southern Texas and Research Solutions for Integrated Eradication

Abstract The potential for reinvasion of the United States by cattle fever ticks, Rhipicephalus (Boophilus) annulatus and Rhipicephalus microplus (Canestrini), which remain established in Mexico, threatens the viability of the domestic livestock industry because these ticks vector the causal agents (Babesia bovis and Babesia bigemina) of bovine babesiosis. The Cattle Fever Tick Eradication Program safeguards the health of the national cattle herd preventing the reemergence of bovine babesiosis by keeping the United States free of cattle fever ticks. Here, the collection of free-living southern cattle tick, R. microplus, 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.

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Research on Integrated Management for Cattle Fever Ticks and Bovine Babesiosis in the United States and Mexico: Current Status and Opportunities for Binational Coordination

Pathogens ◽

10.3390/pathogens9110871 ◽

2020 ◽

Vol 9 (11) ◽

pp. 871 ◽

Cited By ~ 1

Author(s):

Maria D. Esteve-Gasent ◽

Roger I. Rodríguez-Vivas ◽

Raúl F. Medina ◽

Dee Ellis ◽

Andy Schwartz ◽

...

Keyword(s):

Animal Health ◽

Economic Cost ◽

The United States ◽

Boophilus Microplus ◽

Babesia Bovis ◽

Common Interest ◽

Current Status ◽

Bovine Babesiosis ◽

Cattle Fever Ticks ◽

The U.S

Bovine babesiosis is a reportable transboundary animal disease caused by Babesia bovis and Babesiabigemina in the Americas where these apicomplexan protozoa are transmitted by the invasive cattle fever ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus(Boophilus) annulatus. In countries like Mexico where cattle fever ticks remain endemic, bovine babesiosis is detrimental to cattle health and results in a significant economic cost to the livestock industry. These cattle disease vectors continue to threaten the U.S. cattle industry despite their elimination through efforts of the Cattle Fever Tick Eradication Program. Mexico and the U.S. share a common interest in managing cattle fever ticks through their economically important binational cattle trade. Here, we report the outcomes of a meeting where stakeholders from Mexico and the U.S. representing the livestock and pharmaceutical industry, regulatory agencies, and research institutions gathered to discuss research and knowledge gaps requiring attention to advance progressive management strategies for bovine babesiosis and cattle fever ticks. Research recommendations and other actionable activities reflect commitment among meeting participants to seize opportunities for collaborative efforts. Addressing these research gaps is expected to yield scientific knowledge benefitting the interdependent livestock industries of Mexico and the U.S. through its translation into enhanced biosecurity against the economic and animal health impacts of bovine babesiosis and cattle fever ticks.

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Baculoviral Expression of Presumptive OP-Resistance Mutations in BmAChE1 of Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) and Biochemical Resistance to OP Inhibition

Journal of Medical Entomology ◽

10.1093/jme/tjz062 ◽

2019 ◽

Vol 56 (5) ◽

pp. 1318-1323

Author(s):

Kevin B Temeyer ◽

Kristie G Schlechte ◽

William P McDonough

Keyword(s):

United States ◽

The United States ◽

Boophilus Microplus ◽

Cattle Tick ◽

Resistance Mutations ◽

Bovine Babesiosis ◽

Gene Encoding ◽

Southern Cattle Tick ◽

High Level ◽

Tick Resistance

Abstract The southern cattle tick, Rhipicephalus (Boophilus) microplus (Canestrini), transmits bovine babesiosis and anaplasmosis, and is endemic to Mexico, Latin and South America. Rhipicephalus (B.) microplus infestations within the United States are a continuing threat to U.S. cattle producers. An importation barrier between Texas and Mexico keeps the ticks from re-entering the United States. All cattle imported into the United States are dipped in an organophosphate (OP) acaricide and hand inspected for presence of ticks. Tick resistance has developed to most available acaricides, including coumaphos, the OP used in the cattle dip vats. OP-resistance can result from one or more mutations in the gene encoding the enzyme, acetylcholinesterase (AChE), resulting in production of an altered AChE resistant to OP inhibition. Previous research reported a large number of BmAChE1 mutations associated with OP resistance. We report baculovirus expression of recombinant tick BmAChE1 (rBmAChE) enzymes containing a single resistance-associated mutation, to assess their contribution to OP inhibition resistance. Surprisingly, of the naturally occurring BmAChE1 resistance-associated mutations, only D188G resulted in markedly reduced sensitivity to OP-inhibition suggesting that OP-insensitivity in BmAChE1 may result from the D188G mutation, or may possibly result from multiple mutations, each contributing a small decrease in OP sensitivity. Furthermore, an OP-insensitivity mutation (G119S) found in mosquitoes was expressed in rBmAChE1, resulting in 500-2000-fold decreased sensitivity to OP inhibition. Recombinant BmAChE1 with the G119S mutation demonstrated the lack of any structural prohibition to broad and high-level OP-insensitivity, suggesting potential increases in tick OP-resistance that would threaten the U.S. importation barrier to ticks.

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Biosurveillance and Research Needs Involving Area-Wide Systematic Active Sampling to Enhance Integrated Cattle Fever Tick (Ixodida: Ixodidae) Eradication

Journal of Medical Entomology ◽

10.1093/jme/tjab051 ◽

2021 ◽

Author(s):

Allan T Showler ◽

Adalberto Pérez de León ◽

Perot Saelao

Keyword(s):

United States ◽

Coastal Plain ◽

The United States ◽

Boophilus Microplus ◽

South Texas ◽

Knowledge Gap ◽

Active Sampling ◽

Bovine Babesiosis ◽

Research Perspectives ◽

Cattle Fever Tick

Abstract The one-host cattle fever tick, Rhipicephalus (Boophilus) annulatus (Say), and southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini), are important ectoparasitic pests of cattle, Bos taurus L., mostly for transmitting the causal agents of bovine babesiosis. Bovine babesiosis inflicted substantial cattle production losses in the United States before the vectors were eliminated by 1943, with the exception of a Permanent Quarantine Zone in South Texas, a buffer along the Mexico border where the invasive ixodids remain. As suitable hosts, infested white-tailed deer and nilgai antelope populations disperse R. annulatus and R. microplus, which increases the risk for emergence of bovine babesiosis in the United States. A R. microplus incursion first detected in 2016 on the South Texas coastal plain wildlife corridor involved infestations on cattle, nilgai antelope, white-tailed deer, and vegetation. Efforts at passive sampling of Rhipicephalus (Boophilus) spp. on hosts are concentrated in the Permanent Quarantine Zone. Hence, a knowledge gap exists on the full extent of the recent incursions. Area-wide, systematic, active sampling and supportive research, involving the Permanent Quarantine Zone, Temporary Quarantine Zone, most of the coastal plain, and other parts of Texas outside of the quarantine zones, are needed to bridge the knowledge gap. Herein, we provide research perspectives and rationale to develop and implement systematic active sampling that will provide an increasingly accurate assessment of Rhipicephalus (Boophilus) spp. distribution in Texas. We suggest that this is essential to advance integrated vector-borne animal disease eradication approaches for keeping cattle free of bovine babesiosis.

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126 Detection of fecal chemistry changes in cattle infested with the Southern Cattle Tick, Rhipicephalus (Boophilus) microplus

Journal of Animal Science ◽

10.1093/jas/skz053.122 ◽

2019 ◽

Vol 97 (Supplement_1) ◽

pp. 54-54

Author(s):

Brian T Rich ◽

Pete D Teel ◽

Donald B Thomas ◽

Jay Angerer ◽

Douglas R Tolleson ◽

...

Keyword(s):

Near Infrared ◽

Tick Infestation ◽

Blood Feeding ◽

The United States ◽

Boophilus Microplus ◽

Cattle Tick ◽

Spectral Variation ◽

Bovine Babesiosis ◽

Near Infrared Reflectance ◽

Cattle Fever Ticks

Abstract Bovine babesiosis, a highly fatal tick-borne disease of cattle, was eliminated from the United States in the last century through tick eradication programs against 2 species of cattle fever ticks. The threat to the U.S. cattle industry continues through tick introductions from Mexico. The standard method of detecting Cattle Fever Ticks [Rhipicephalus (B.) annulatus and R. (B.) microplus] in the state-federal tick eradication program is physical examination of restrained cattle to find attached ticks. New methods of detecting tick-infested cattle could improve reliability and reduce animal stress. The objective of this study was to determine whether changes in fecal chemistry induced by tick infestation was detectable using near-infrared reflectance spectroscopy (NIRS). Fecal samples were collected daily from 6 stanchioned Bos taurus yearling heifers (initial mean weight 163.3 kg +/- 4.7 kg) at the USDA Cattle Fever Tick Research Laboratory, Edinburg, TX, before, during, and after an infestation of 5000 R. (B.) microplus larvae. Cluster analyses were conducted using GRAMS IQ for NIR spectra in the 576–1126 nm range to test for fecal chemistry changes different from pre-infestation condition, and coincident with the biological phases of the tick infestation. The first three factors of spectral variation accounted for 87.87% of spectral variation among all samples. Factors 1, 2, and 3 had F-Ratios for the Reduced Eigenvalues of 941.59, 387.44, and 221.79, respectively. Three-dimensional analysis for these 3 factors shows shifts in sample clusters away from pre-infestation and coincident with progressive tick blood-feeding and post-infestation recovery. We conclude that fecal NIRS may provide a tool for detection of tick-infested cattle; however, further testing is needed to determine the sensitivity of detection on cattle with varying levels of tick burden, and a protocol developed and evaluated for fecal sampling under field conditions

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Landscape Ecology of Rhipicephalus (Boophilus) microplus (Ixodida: Ixodidae) Outbreaks in the South Texas Coastal Plain Wildlife Corridor Including Man-Made Barriers

Environmental Entomology ◽

10.1093/ee/nvaa038 ◽

2020 ◽

Vol 49 (3) ◽

pp. 546-552 ◽

Cited By ~ 2

Author(s):

Allan T Showler ◽

Adalberto Pérez de León

Keyword(s):

Coastal Plain ◽

Storm Surges ◽

Boophilus Microplus ◽

South Texas ◽

The South ◽

Wildlife Corridor ◽

Mud Flat ◽

Mexico Border ◽

Saline Habitats ◽

Cattle Fever Tick

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 in 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 in the South Texas coastal plain wildlife corridor. Ixodid distribution on the wildlife corridor is strongly influenced by habitat salinity. Saline habitats, which constitute ≈25% 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.

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Analysis of Babesia bovis infection-induced gene expression changes in larvae from the cattle tick, Rhipicephalus (Boophilus) microplus

Parasites & Vectors ◽

10.1186/1756-3305-5-162 ◽

2012 ◽

Vol 5 (1) ◽

Cited By ~ 19

Author(s):

Andrew M Heekin ◽

Felix D Guerrero ◽

Kylie G Bendele ◽

Leo Saldivar ◽

Glen A Scoles ◽

...

Keyword(s):

Gene Expression ◽

Boophilus Microplus ◽

Babesia Bovis ◽

Cattle Tick

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Observations on the dispersal of larvae of the cattle tick Boophilus microplus (Can.)

Bulletin of Entomological Research ◽

10.1017/s0007485300003588 ◽

1970 ◽

Vol 59 (4) ◽

pp. 595-604 ◽

Cited By ~ 8

Author(s):

I. J. Lewis

Keyword(s):

New South ◽

New South Wales ◽

Buffer Zone ◽

Boophilus Microplus ◽

Cattle Tick ◽

Research Station ◽

Bovine Babesiosis ◽

Buffer Zones ◽

South Wales ◽

Strong Winds

Dispersal of the larvae of the cattle tick Boophilus microplus (Can.) was studied in connection with problems of controlling and eradicating this pest and bovine babesiosis in New South Wales. Larval ticks were recovered by pressing flannelette-covered boards on to the pasture or litter surface, or sampling with cattle. Many of these larvae were capable of completing parasitic development.Strong winds were an important factor in determining the distance travelled, as the longest journeys in pasture were for the most part in the directions in which the larvae would have been carried by recorded strong winds. Much of the dispersal is accomplished when larvae are transferred from one grass blade to another moving in the wind, but a great number of airborne larvae were captured on tanglefoot-covered traps. Movement by wind was clearly demonstrated over short pasture, up to 100 ft and possibly as far as 260 ft from the point of hatching. In long grass one larva travelled 83 ft, but in scrub and forest the greatest distance travelled was 15 ft. Many larvae that travelled long distances were capable of completing development on cattle.Tick larvae could be transported by casual hosts and then dropped in a viable condition. A horse carried larvae for 900 ft, a rat and cockerels 100 ft, a magpie in flight 600 ft, and a pigeon in flight half a mile. A horse dipped six days earlier in ethion dropped live and viable larvae after transporting them 150 ft.Security has been improved against the movement of larvae from the Cattle Tick Research Station, Wollongbar, New South Wales, to neighbouring properties, and from Queensland into New South Wales, by widening existing buffer zones to 330 ft. Inspectoral staff are now required to spray themselves and their horses before re-entering New South Wales from the buffer zone.

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