Background/Question/Methods Plant-insect-virus interactions have been almost exclusively studied in agricultural systems, leaving wild habitats mostly unexplored. Wild plants are important to study in terms of plant-insect-virus interactions because of their heterogeneity compared to crop plants, suite of anti-herbivore defenses, and diversity of life history traits. Thus, the field of virus ecology is now focusing on new research systems with wild plants. The general belief about wild plants is that they are resistant to infection and suffer no fitness costs. Our aim is to test the hypothesis that wild plants experience reduced fitness due to virus infection using a new system: Cucurbit aphid-borne yellows virus and aphid vector Aphis gossypii, and two perennial plants native to the region and congeneric with crops - Cucurbita foetidissima and C. palmata. In observational field studies, we monitored for herbivore damage and disease pathology in wild-growing individuals with known infection status in reserves in Riverside County in Southern California. In corresponding controlled greenhouse experiments, we tracked disease progression and proxies for plant fitness after aphid inoculation at 2, 4, 6 and 8 weeks post inoculation. At 8 weeks, we weighed root and shoot tissue and collected samples for quantitative-reverse transcription-PCR to quantify virus amount in the individuals. At 2 and 4 weeks post infection, we also tested the feeding behavior of the insect vector using electrical penetration graph technique. Results/Conclusions Here, we present data on the differential susceptibility by plant species, with evidence of negative effects on shoot and root development, as well as the feeding (transmission) behavior of the aphid. We also present data on plant growth progression over the growing season, including floral phenology and vine growth for both cucurbit species. Our work contributes to the growing body of research in virus ecology showing that wild plants are at risk from exotic pathogens.
