Data from: A laboratory study estimating blacklegged tick adhesion rates to host species of varying permissiveness
Data files
Mar 12, 2026 version files 93.81 KB
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AdhereData.csv
83.73 KB
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AdhereHostInfo.csv
559 B
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README.md
3.93 KB
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TickCollection.csv
5.59 KB
Abstract
Host species vary tremendously in their permissiveness to blacklegged tick (Ixodes scapularis) feeding and their capacity to transmit pathogens to them. Thus, the host species ticks feed on impacts both tick population growth and infection prevalence. Given the importance of the bloodmeal to tick fitness there may be selection pressure for behavioral mechanisms that ensure they feed on more permissive hosts. We hypothesized that, if ticks have evolved host preferences, adhesion rates (when ticks get onto hosts) will increase with host permissiveness. We conducted a laboratory experiment to estimate larval and nymphal adhesion rates on four host species, representing a range of permissiveness (in descending order: Peromyscus leucopus, Tamias striatus, Sciurus carolinensis, and Didelphis virginiana) during standardized encounters using an apparatus designed to generate repeatable host-tick contacts. We found adhesion rates were essentially equivalent on the most (P. leucopus) and least permissive species (D. virginiana) and much higher on the second least permissive species (S. carolinensis). We also found the maximum adhesion probability for both larvae and nymphs declined with estimated time since emergence, though the effect was more pronounced in larvae. These results contradict both our expectation that adhesion to hosts is biased towards more permissive hosts and the widely held assumption that ticks equally attempt feeding on all host species. However, adhesion represents just one stage of ticks’ host selection process, and whether these adhesion rates in our study translate into actual feeding rates, and thus impact tick population and infection dynamics, remains an open question.
These data come from an experiment designed to determine larval and nymphal blacklegged ticks (Ixodes scapularis) adhesion rates to hosts, given contact with that host, and if adhesion rates to host species scale with the permissiveness of that species. We used wild caught white-footed mice (Peromyscus leucopus), eastern chipmunks (Tamias striatus), gray squirrels (Sciurus carolinensis), and Virginia opossums (Didelphus virginiana) as our host species, as these species span the spectrum from high-quality to very low-quality hosts. We constructed an apparatus in which individual hosts walked past ticks and recorded the amount of time individual ticks were in contact with the host, and whether or not they adhered to the host.
Description of the data and file structure
AdhereData.csv includes data measuring the time individual ticks spent in contact with a host, and whether or not they attached. Each row is data for a single tick during a trial. Columns in this csv are:
- HostID: The unique ear tag of a host individual.
- LifeStage: If the tick was a larva (L) or a nymph (N).
- Trial: The trial number (1, 2, or 3). Each host was used in up to 6 trials, 3 with larvae and 3 with nymphs.
- TickID: During examinations of trial videos each tick was given a unique number.
- Contacted: If a tick was contacted by a host (1) or not (0).
- StartCon: If a tick attached to a host, StartCon is the amount of contact (measured in seconds) that the tick had with the host prior to the start of the contact interval when attachment occurred. If the tick attached during the first host contact, we entered 0.01. If the tick did not attach, it is the total time the tick was in contact with the host.
- EndCon: If a tick attached to a host, EndCon is the end of the contact interval when attachment occurred. If the tick did not attach, it is the total time the tick was in contact with the host.
- Adhered: If a tick attached to a host (1) or not (0).
AdhereHostInfo.csv includes information on the host individuals used in trials. Columns included are:
- HostID: The unique ear tag of a host individual.
- Species: The abbreviated species ID of that host individual. PL = Peromyscus leucopus, TS = Tamias striatus, SC = Sciurus carolinensis, and DV = Didelphus virginiana.
- Year: The year the host was trapped and used in trials (2021 or 2022).
TickCollection.csv includes information on tick ages and time since collection for each trial. Columns included are:
- HostTrial: Unique trial ID created by combining HostID, the tick life stage used in the trial, and the trial number.
- TrialDate: The date the trial was conducted (MM/DD/YY).
- TickCollect: The date ticks used in the trial were collected (MM/DD/YY).
- DateEmerge: The approximate date when larvae or nymphs would have begun actively host seeking (MM/DD/YY). Our estimates are derived from Levi et al. 2015. Emergence for nymphs and spring larva = May 1st, and emergence for summer larva = July 1st.
Code/Software
All models are specified using Stan code (_.stan files) which are run in R. The Stan models are as follows:
- m_dur_a.stan: Model with delta as a function of age, no host species effect.
- m_dur_ah.stan: Model with delta as a function of age, including a host species effect.
- m_dur_a_hatch.stan: Model with delta as a function of age and hatch source, no host species effect. Only for larval data.
- m_dur_a_hatch.stan: Model with delta as a function of age and hatch source, including a host species effect. Only for larval data.
- m_dur.stan: Model with constant delta and no species effect.
- m_dur_h.stan: Model with constant delta, including a host species effect.
The AttachmentAnalyses.pdf and similar files contain the R code to run the above Stan models and generate paper figures.