What makes a tick-host encounter successful? Isolating the effects of host and tick qualities on rates of larvae adhering to hosts
Data files
Mar 21, 2026 version files 32.54 MB
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FakeHost_2024.html
5.98 MB
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FakeHost_2024.qmd
28.66 KB
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FakeHost_app.mov
26.51 MB
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FakeHost_FurAge.csv
5.49 KB
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FakeHost_SD.csv
14.02 KB
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README.md
3.99 KB
Abstract
Blacklegged ticks (Ixodes scapularis) require a single bloodmeal from one of many potential host species during each of their three life stages. However, host species vary tremendously in their permissiveness for ticks. Given the variation in tick survival on hosts, we would expect ticks to have evolved mechanisms that increase their probability of feeding on highly permissive species. However, we know little of what happens during an encounter between a tick and a passing host. To explore the influence of host and tick qualities on the probability ticks adhere to hosts, we constructed an apparatus in which an artificial host passed over I. scapularis larvae, simulating hosts walking over ticks. This allowed us to control isolated qualities of the host and ticks we hypothesized to be important and observe how many larvae adhered to hosts. In one experiment, larvae were twice as likely to adhere to mouse fur than opossum fur, and even less likely to adhere to drag cloth corduroy. However, fur type had no apparent effect in a second study. Instead, the probability larvae adhered to a host increased rapidly with the duration of contact, saturating by ~1 s regardless of fur type, and slightly influenced by host speed. Even with the longest contact times only ~2/3 of larvae adhered to a host. This probability declined with larval age. Collectively, our results suggest ticks may attempt to adhere to any host they contact, perhaps because contacts are rare and often brief, but not all host-seeking ticks are in a state where they can or will adhere.
These data come from an experiment designed to isolate the qualities of hosts or ticks that influence the probability larval blacklegged ticks (Ixodes scapularis) adhere to hosts, given contact with the host. We constructed an apparatus in which an artificial host passed over I. scapularis larva in a controlled manner, simulating hosts walking over ticks. Each trial consisted of an artificial host passing over 10 larvae, each larvae isolated on a single tine of a comb, and then counting how many ticks got onto the fur. Our artificial hosts were constructed from strips of corduroy and fur from frozen, unprocessed Virginia opossums (Didelphus virginiana) and white-footed mice (Peromyscus leucopus). Larvae were obtained from Oklahoma State University's Tick Rearing Facility. We examined host and tick traits that could influence adhesion in two experiments.
Experiment 1 examined the impact of host fur texture and tick age. We ran trials using 5 cm by 5 cm corduroy, opossum fur, and mouse fur artificial hosts. Trials were conducted over multiple weeks, and tick age was determined as the number of days between when 25% of ticks hatched and the date the trial was conducted.
Experiment 2 examined the impact of the speed and duration of contact. We isolated speed from duration by running trials with 5 cm and 20 cm long hosts passing over ticks at 3 different speeds, such that longer hosts moving slowly contacted ticks for the same duration of time as shorter hosts moving quickly. We conducted these experiments using mouse and opossum hosts.
Description of the data and file structure
Data are the status of ticks after a single pass of the artificial host. We have separate data files for Experiment 1 (FakeHost_FurAge.csv) and Experiment 2 (FakeHost_SD.csv). Both data files share the same structure and columns, though the file for Experiment 2 contains an additional column for speed. Each row is data for a single trial. The shared columns for each data frame are the following:
- TrialID: A unique identifier for each trial. The first 6 digits are the date the experiment was conducted.
- FurID: An ID for the artificial host used in a trial. Opo = opossum fur, Mo = mouse fur, and Co = corduroy. Furs that end with "1" are 5cm long hosts. Furs that end with "l" are 20cm long hosts.
- TicksIn: Number of ticks placed in the apparatus at the start of a trial. Should always be 10.
- Remain: Number of ticks that remain in their starting position after the host pass.
- L1-L10: Location of individual ticks on fur after host pass for a trial. L1-10 refers to the tine a tick began the trial on. Values of >1 represent the distance in cm from the leading edge of the fur. Values = 0 represent ticks that remained on their starting tine. Values = NA represent ticks that either escaped or were missing after the trial pass.
- Adhere_Tot: Total number of ticks found on the fur after the host pass for a trial.
- Escape: Number of ticks found in the water surrounding the comb or apparatus after the host pass.
- Missing: Ticks that were not recovered after the trial pass.
- Temp: Ambient temperature of the room during the trial. Units = Celsius. "n/a" means the data was not recorded for that trial, though the value was likely similar to other trials conducted on the same day.
- H: RH of the room during the trial. "n/a" means the data was not recorded for that trial, though the value was likely similar to other trials conducted on the same day.
FakeHost_SD.csv includes an additional column:
- Speed: the Speed in cm/s the fake host passed over the ticks.
Code/Software
The FakeHost_2024.qmd and similar files contain the R code to run statistical analyses of the above data and generate paper figures.
Additional Files
FakeHost_app.mov is a video of a single pass of the artificial host over ticks.
