The impact of predator non-consumptive effects on transmission of a plant virus

It is well documented that arthropod predators play an important role in insect pest control. Along with predation, non-consumptive effects may also alter the feeding behavior of plant virus vector species, and thus alter virus transmission efficiency. We tested this hypothesis by exposing Maize Fine Streak Virus (MFSV) inoculative leafhoppers to corn plants in the presence and absence of jumping spiders or lady beetles in mesocosm and macrocosm arenas. Mesocosm trials consisted of a single plant enclosed in an 8” by 2.75” tube, with five inoculative leafhoppers and a predator; predator choices included a single jumping spider or five lady beetles per plant. Macrocosm arenas were 10 plants lined-up diagonally in 2 x 2 x 4 foot cages, with 50 inoculative leafhoppers and a caged spider propped against each plant. In mesocosm arenas, the presence of jumping spiders in close proximity to the leafhoppers led to a decrease in transmission of MFSV. However, in larger-scale macrocosm studies, there was no change in virus transmission.  The presence of lady beetles did not impact virus transmission. These results suggest that certain predators in close contact with vector species could potentially limit transmission of plant viruses.