Effects of a crop-associated virus on host performance and aphid vector behavior

Crop-associated viruses are causative agents of plant diseases (mosaics, stunting,
mottling) that result in reduced crop marketability and yield losses in agriculture. Virus effects on plants can directly and indirectly alter insect behavior and fitness. Depending on transmission mechanism, virus effects on insect behavior can be conducive to virus spread. Cucurbit aphid-borne yellows virus (CABYV) is a plant virus that has economic impact in cucurbit-growing regions around the world. It is transmitted by persistent, non-propagative transmission mechanism by two aphid species, Aphis gossypii Glover and Myzus persicae (Sulzer). We found that this virus infects native, perennial plants in three Southern California reserves. In wild plants, viruses can reduce plant fitness through effects on survival, inflorescence production, and seed production, but very few studies address the interaction between wild plants, virus, and insect vectors. Here, we test the effects of CABYV on both the host and vector. We predict that the infected wild cucurbits will have reduced above- and below-ground masses, and test numerous other proxies for fitness in greenhouse experiments. We also predict that A. gossypii will perform better on virus infected plants, and will also feed in ways that are conducive to transmission in experiments using electrical penetration graphing technique.