Our paper on the community ecology of plant viruses was accepted in American Naturalist! In it, we use a three-virus, two-vector, one-plant model parameterized with tons of empirical data on Barley Yellow Dwarf Viruses to study the mechanisms that maintain virus coexistence. It turns out that multiple virus species coinfecting individual plants is critical: without coinfection, viruses couldn't coexist, but even very rare coinfections (8% success rate) strongly promote coexistence. But coinfection alone isn't enough. A tradeoff between vector generality (using more than one vector species) and specialization (transmitting efficiently in a single vector) sustains the coexistence of two closely related BYDV species that strongly compete. Finally, competitive exclusion or coexistence depends on aphid density in interesting ways; for example, vector specialist virus MAV can exclude vector generalist PAV when their shared vector is common, unless a second vector is also abundant. And even when long-term competitive exclusion occurs, we observe a lot of coinfected plants en route to exclusion. This work tells a lot about what kinds of pathogen coexistence and life history tradeoffs can sustain diverse pathogen communities in the face of strong competition for hosts and vectors.

Mordecai, E.A., Gross, K., Mitchell, C.E. Within-host niche differences and fitness tradeoffs promote coexistence of plant viruses. in press. American Naturalist.