Skip to main content
ARS Home » Research » Research Project #440622

Research Project: Predilection Sites of Larvae, Nymphs, and Adults of Rhipicephalus Microplus

Location: Cattle Fever Tick Research

Project Number: 3094-32000-042-071-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Jul 15, 2021
End Date: Jun 14, 2023

Objective:
1. Determine the predilection sites for R. microplus larvae and nymphs on cattle. 2. Evaluate tactile tick infestation detection with actual tick location and quantification.

Approach:
Six Bos taurus heifers or steers will be used in a stall trial and artificially infested with R. microplus larvae. At 4-5 days post-infestation, the animals will be inspected by an ARS caretaker experienced in tick detection, and the number and location of larvae found on each animal will be recorded. Hides from three animals will be processed and archived (frozen) until further examination by Cooperators. On day 9-10 post-larval infestation, attached nymphs and remaining larvae will be identified. The remaining three animals will be inspected by the trained inspector again, and the number and location of larvae and nymphs mapped and recorded. Hides from these three animals will be processed and archived (frozen) until further examination by Cooperators. To gather detailed information on tick density, survival (to inspection date) and distribution, the frozen hide will be visually inspected, and the number of larvae and nymphs found in each section will be recorded as well as hair length. Following the visual search, the hides will be treated using a modified dissolution technique and the ticks will be recovered by filtration. The larvae and nymphs recovered from the hides will be mapped to the hide sections allowing for the determination of density and distribution. An overall assessment will be made of percent survival by comparing infestation number to tick recovery number (for each life stage). Using this approach, the accuracy of tactile inspection as performed by a trained inspector will be compared to the number of larvae and nymphs recovered from the hides. Such information will be highly informative for future tick inspections and improve the security of the U.S. cattle industry.