Incorporation of exotic plants into the diets of native herbivores is a common phenomenon, influencing interactions with natural enemies and providing insight into the tritrophic costs and benefits of dietary expansion. We evaluated how use of an exotic plant, Plantago lanceolata, impacted immune performance, development, and susceptibility to pathogen infection in the neotropical herbivore Anartia jatrophae (Lepidoptera: Nymphalidae). Caterpillars were reared on P. lanceolata or a native plant, Bacopa monnieri, and experimentally infected with a pathogenic virus, Junonia coenia densovirus. We found that virus-challenged herbivores exhibited higher survival rates and lower viral burdens when reared on P. lanceolata compared to B. monnieri, though immune performance and development time were largely similar on the two plants. These findings reveal that use of an exotic plant can impact the vulnerability of a native herbivore to pathogen infection, suggesting diet-mediated protection against disease as a potential mechanism facilitating the incorporation of novel resources.

Methodological details pertaining to this dataset are described in: Muchoney, N.D., Bowers, M.D., Carper, A.L., Teglas, M.B., Smilanich, A.M. Accepted. Use of an exotic host plant reduces viral burden in a native insect herbivore. Ecology Letters.

Muchoney_et_al_2022_FieldSurvey.csv: This file contains the dataset presented in the "Field Survey" section of our publication. Descriptions of column headings and units are provided in the file "README.md".

Muchoney_et_al_2022_LabExperiment.csv: This file contains the dataset presented in the "Laboratory Experiment" section of our publication. Descriptions of column headings and units are provided in the file "README.md".

Muchoney_et_al_RCode.R: This file contains annotated R code used to perform the statistical analyses presented in our publication. All analyses utilize data provided in the file “Muchoney_et_al_LabExperiment.csv".