Project : USDA ARS

ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » Cattle Fever Tick Research Unit » Research » Research Project #436694

Research Project: Integrated Pest Management of Cattle Fever Ticks

Location: Cattle Fever Tick Research Unit

2022 Annual Report

Objectives
Objective 1 Develop population genetic and ecological methods to improve cattle fever tick surveillance. Objective 2: Develop methods to control ticks using biocontrol, botanicals and new acaricides.

Approach
Cattle fever ticks, Rhipicephalus microplus and R. annulatus, are invasive pests that remain a threat to the livestock industry. They were eradicated from the United States in 1943; however, they remain established in Mexico and these populations tend to recolonize suitable habitats north of the Rio Grande. Cattle fever ticks transmit the microbes that cause bovine babesiosis and anaplasmosis. Significant cattle damage and economic loss would result if bovine babesiosis re-emerged in the United States. Research on new technologies to improve Integrated Pest Management (IPM) of cattle fever ticks is needed for implementation in the Cattle Fever Tick Eradication Program (CFTEP). This Program is operated in the Permanent Quarantine Zone established in south Texas along the Rio Grande to eliminate incursions from Mexico. The overall goal of this project is to conduct research on risk assessment and biology, surveillance, control, and monitoring and sustainability to improve integrated cattle fever tick management. The outcomes of this research will be effective, long-term adaptable technological solutions for the challenges that the CFTEP is facing. These include climate variability, acaricide resistance, involvement of native and exotic wildlife as alternative tick hosts, and the economic impact of tick outbreaks. The project will also benefit transdisciplinary efforts to achieve optimal health for animals, humans, and the environment, a concept known as “One Health”, by adapting this research to tick disease vectors expanding their range and exotic ticks that threaten animal and human health in the United States.

Progress Report
In support of Subobjective 1A, integrate cattle fever tick genetic data with geographic information system (GIS) tools to enhance understanding of the geographic source and population structure of ticks causing outbreaks, ARS scientists have continued collaborative efforts with scientists at The Pathogen and Microbiome Institute, Northern Arizona University, to assess presence of sequence variations associated with cattle fever tick resistance to permethrin as well as sequence variations that are informative for distinguishing geographically separated populations of cattle fever ticks. Results are routinely provided to the USDA-APHIS-VS Cattle Fever Tick Eradication Program (CFTEP) in support of programmatic efforts. In addition, ARS scientists and collaborators are using next-gen sequencing approaches to potentially increase the number of informative sequence variations that can be used when comparing cattle fever tick populations within and between U.S. and Mexico isolates. Tick samples have been identified for pooling, library construction, and sequencing on the Illumina platform. In support of Subobjective 1B, enhance GIS-based tools for cattle fever tick surveillance, ARS researchers partnered with the ARS Partnerships for Data Innovations (PDI) team to develop a FieldMaps tool for the CFTEP to streamline data entry and enable real-time access to the fever tick infestation database. This FieldMaps tool was initially beta tested by select CFTEP field inspectors and has now been officially launched for use by the eradication program. Over 100 CFTEP field inspectors in eight different county work areas have access to this tool for real-time entry of fever tick infestation data. This new system allows CFTEP inspectors in the field to record fever tick outbreak data from their phones directly to an online map layer that can be quickly accessed by program personnel and ARS researchers. This FieldMaps tool has significantly decreased data entry workflow, enabled rapid identification of at-risk areas in south Texas, and allowed for faster programmatic decision making. In support of Subobjective 1C, develop novel and refine existing cattle fever tick sampling methods, ARS researchers evaluated several methods to mechanically collect fever ticks from the environment including the “tick-vac” and the “tick bot”. Field studies were conducted in naturally infested fever tick habitats to compare these two collection methods to the previously tested “tick trouser” method. Additionally, two other novel tick sampling methods, 1- sampling bovine feces for detection of biochemicals as an indicator of tick infestation and 2-using Raman spectroscopy to sample for tick fecal residues on cattle, were developed and tested in collaboration with Texas A&M University. Both methods show promise for use as a non-invasive, non-destructive method for detecting tick infestations. In support of Subobjective 2A, refine the remotely activated sprayer to treat cattle fever tick infestations in nilgai and white-tailed deer, ARS researchers evaluated the efficacy of Barricade® fire gel as a UV protectant to extend the life of entomopathogenic nematodes that are utilized in a spray in the remotely activated sprayers for controlling cattle fever ticks on wildlife. Studies indicated that Barricade® has the potential to improve the efficacy of Steinernema riobrave and Heterorhabditis floridensis, two nematodes that kill cattle fever ticks, by reducing mortality and desiccation. Additionally, remotely activated sprayers were utilized in a field study in Cameron County to evaluate whether use of the sprayers at corn feeders impacted white-tailed deer use of the feeders. Camera observations indicated that use of the sprayers at the feeders, either only spraying water or the botanical pesticide Stop the Bites®, did not deter the deer from using the feeders. These results suggest that use of remotely activated sprayers for the treatment of fever ticks on deer that utilize corn feeders may be operationally feasible for use by the CFTEP in south Texas. In support of Subojective 2C, evaluate natural botanicals, abrasives, and dessicants against cattle fever ticks for use in sensitive wildlife areas, in vivo and in vitro studies were continued to evaluate the efficacy of desiccant dusts and botanical products (nootkatone, cedar oil, and Stop the Bites®) for controlling lone star and cattle fever ticks. In support of Subjective 2D, discover and evaluate classical biological control agents for CFT, ARS researchers developed and tested methods to collect Ixodiphagous parasitoid wasps using cattle fever tick infested cattle in the tick’s native range including Vietnam, Bulgaria, and Greece. To date no Ixodiphagus wasp have been conclusively reared from fever tick nymphs, but studies are underway to expose fever tick larvae in Vietnam to determine if this off-host life stage is parasitized. Preliminary DNA evidence indicates that Ixodiphagus wasps do parasitize fever tick larvae. Discovery and establishment of a specialist parasitoid for cattle fever ticks could have significant impacts and enhance the efficiency and sustainability of the CFTEP in the transboundary region between Texas and Mexico and worldwide where cattle fever ticks are invasive. In support of Subobjective 2E, evaluate novel long-acting (LA) acaricide formulations to reduce the number of systematic treatments needed to manage cattle fever tick infestations, protocols were developed and approved to evaluate the therapeutic and residual efficacy of a pour-on formulation of fluralaner for controlling Amblyomma mixtum and cattle fever ticks infesting cattle. Pasture studies to evaluate varying doses of macrocyclic lactones (doramectin, eprinomectin, and moxidectin) for fever tick control were completed and tick efficacy and pharmacokinetic data are being analyzed. If efficacious, these treatments could reduce the number of treatments needed to manage cattle fever tick infestations on quarantined cattle reducing treatment costs and losses due to animal injury.

Accomplishments
1. Tick identification using spectroscopic analysis of feces. Ticks are blood-feeding parasites that vector pathogens of medical and veterinary importance and cause billions of dollars in economic losses globally each year. New methods for early detection of ticks, in particular exotic or invasive species, are needed. Timely detection of tick species on hosts like cattle can cease the spread of devastating diseases like babesiosis and anaplasmosis. ARS researchers in Edinburg, Texas, in collaboration with Texas A&M University, found that Raman spectroscopy can be used as a non-invasive, non-destructive method to identify ticks by their feces. Further development of this surveillance method could lead to faster detection of exotic or invasive tick species or significantly reduce the time and cost of inspecting livestock as part of a tick management or eradication program.

2. Cattle fecal chemistry changes with tick development. Cattle fever ticks are a globally important ectoparasite of cattle and are known to harbor pathogens that can cause diseases in cattle like cattle fever and anaplasmosis. Detection of cattle fever ticks on cattle is a critical component of the south Texas based Cattle Fever Tick Eradication Program. Current detection practices include restraining cattle and inspecting the hair coat of each animal individually by hand. ARS researchers in Edinburg, Texas, and Parlier, California, in collaboration with Texas A&M University, found near infrared reflectance spectroscopy (NIRS) could be used to detect fecal chemistry changes in cattle that had been infested with fever ticks. This finding indicates that NIRS analysis of cattle feces could be utilized for detecting cattle fever ticks infesting cattle in south Texas without having to restrain cattle or inspect each animal by hand, saving valuable time and resources.

3. Cattle fever tick interactive database developed. The Cattle Fever Tick Eradication Program (CFTEP) is a collaborative effort among state and federal agencies, including USDA, Animal and Plant Health Inspection Service (APHIS), ARS, and the Texas Animal Health Commission. Fever tick quarantine regulations are enforced along 500 miles of the Rio Grande River border with Mexico to prevent fever ticks carrying disease pathogens from entering the United States. With the help of ARS, the CFTEP maintains land ownership records, fenceline locations, and tick inspection data for this area. Compiling this data into a format that fever tick researchers and CFTEP personnel can easily access is time consuming and involves input of over 3000 datapoints per month. To better streamline this process, ARS researchers in Kerrville, Texas, partnered with the ARS Partnerships for Data Innovations team to develop a new data entry platform that utilizes the FieldMaps tool by Esri. This new phone-based data entry system allows CFTEP inspectors in the field to record fever tick outbreak data directly to an online map layer that program personnel and ARS researchers can access in real time leading to faster analysis of tick outbreaks and identification of at-risk areas.

U.S. DEPARTMENT OF AGRICULTURE

Cattle Fever Tick Research Unit: Kerrville, TX