Investigating the effects of temporal and vegetation variables on cattle fever tick Rhipicephalus (Boophilus) microplus questing patterns

Authors: HERNANDEZ, ALONDRA - University Of Texas Rio Grande Valley; Maestas, Lauren; MAESTAS, SARAH - University Of Texas Rio Grande Valley

Submitted to: Subtropical Agriculture and Environments
Publication Type: Proceedings
Publication Acceptance Date: 2/27/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cattle Fever Ticks (CFT) pose significant threats to cattle health by transmitting the agents of bovine babesiosis and anaplasmosis. To enhance our understanding of CFT biology and to optimize monitoring efforts, we carried out a study to examine the effects of season and habitat on questing abundance of larval CFT. This approach aims to assess daytime variations in CFT abundance, considering potential changes in daily activity linked to temperature and time of day. We carried out weekly sampling in artificially infested filed plots at the USDA Cattle Fever Tick Research Unit. We sampled two habitat types, consisting of mesquite-dominated plots and buffelgrass-dominated plots, with three repetitions at each time point in each habitat type. Ticks were collected via tick drag at two daily time points: early morning, and after 12pm to capture potential variations of questing activity. Temperature and humidity were recorded during each sampling event. Each experimental plot was infested with ~20,000 lab-reared R. microplus larvae weekly, three days before weekly sampling. Data collected mid-April 2024 – October 2024 was analyzed using a negative binomial regression. The number of ticks collected significantly differed by week of collection, and by temperature, with temperature having a negative effect on questing tick abundance. No significant effects of habitat type, humidity or time of day were detected. We are continuing this sampling for a full year to investigate how seasonal environmental variables such as temperature influence seasonal tick activity. This research allows us to assess the effects of habitat and environmental variables on larval cattle fever tick questing abundance to provide insights for tick management efforts.

Technical Abstract: Cattle Fever Ticks (CFT), specifically R. (B.) microplus, pose significant threats to cattle health by serving as vectors for bovine babesiosis and anaplasmosis. To enhance our understanding of CFT dynamics and optimize monitoring efforts, we carried out a study to examine the effects of temporal and habitat variables on questing abundance of larval CFT. This approach aims to assess diurnal variations in CFT abundance, considering potential fluctuations linked to temperature and time of day. We carried out weekly sampling in artificially infested plots at the USDA Cattle Fever Tick Research Unit. We sampled two habitat types, consisting of mesquite-dominated plots and buffelgrass-dominated plots, with three reps at each time point in each habitat type. Ticks were collected via tick drag at two daily time points: early morning, and after 12pm to capture potential variations of questing activity. Temperature and humidity were recorded during each sampling event. Each experimental plot was infested with ~20,000 lab-reared R. microplus larvae weekly, three days before weekly sampling. Data collected mid-April 2024 – October 2024 was analyzed using a negative binomial regression. The number of ticks collected significantly differed by collection period, and by temperature, with temperature having a negative effect on questing tick abundance. No significant effects of habitat type, humidity or time of day were detected. We are continuing this sampling for a full year to investigate how seasonal environmental variables such as temperature influence seasonal tick activity. This research allows us to assess the effects of habitat and environmental variables on larval cattle fever tick questing abundance to provide insights for tick management efforts.