ABSTRACTS SUBMISSION

169_Nadya Muchoney ‐ University of Nevada, Reno ‐ États‐Unis [email protected]

Use of an introduced host plant enhances resistance against densovirus infection in a native herbivore

Nadya D. Muchoney [1], M. Deane Bowers [2], Adrian L. Carper [2], Mylene Ogliastro [3], Angela M. Smilanich [1]

[1] Department of Biology, University of Nevada, Reno, USA; [2] Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA; [3] INRA, University of Montpellier, France

Incorporation of introduced plant species into the diets of native insect herbivores is a common phenomenon; however, herbivore performance is often reduced when utilizing these novel host plants, compared to native host plants. Investigating the impacts of novel host plant use on herbivore interactions with natural enemies may provide additional insight into the evolutionary costs and benefits of dietary expansion. Here, we evaluated the hypothesis that improved defense against infectious disease may facilitate herbivore persistence on introduced plants that confer relatively poor developmental performance. To address this hypothesis, we experimentally evaluated how use of an introduced host plant, Plantago lanceolata, influenced interactions between a native herbivore, the white peacock ( jatrophae), and an entomopathogen that occurs naturally in A. jatrophae populations, Junonia coenia densovirus (JcDV; Parvoviridae). A. jatrophae caterpillars were reared on either P. lanceolata or a native host plant, , and a subset of individuals was orally inoculated with JcDV. We then measured three immune parameters, along with development rate and mortality, in virus‐challenged and control individuals. While survival of unchallenged individuals did not differ between the two host plants, survival of individuals challenged with JcDV was substantially higher when utilizing the introduced plant, P. lanceolata. Individuals using P. lanceolata also exhibited lower viral loads than those using the native plant, though immune performance did not differ between the two diets. Additionally, JcDV‐challenged individuals exhibited faster development, but lower pupal weights, than controls. These results indicate that use of an introduced plant confers increased resistance against JcDV infection in A. jatrophae, which may promote the continued use of P. lanceolata in populations experiencing high JcDV pressure. Overall, these findings illustrate that disease outcomes can differ markedly in herbivores utilizing different host plant species, highlighting the importance of considering interactions with pathogens within investigations of diet breadth evolution.

1. What is your pathogen? Multiple options possible (e.g. if working on coinfections)

Other viruses : Junonia coenia densovirus

2. On a scale of 1‐5 is your work mostly eco/epidemiological or evolutionary? 2

3. On a scale of 1‐5 is your work mostly theoretical or experimental/empirical? 5 (100% empirical)

Extraction du 10/5/2021