Influence of nonhost plant diversity and natural enemies on the potato leafhopper, Empoasca fabae, and pea aphid, Acyrthosiphon pisum, in alfalfa

摘要: We examined the effects of nonhost plant diversity and predators on potato leafhopper, Empoasca fabae (Harris), pea aphid, Acyrthosiphon pisum their primary host plant, alfalfa, Medicago sativa L. Potato leafhopper intensity (i.e., leafhoppers/alfalfa stem density) damage hopperburn) were significantly greater in alfalfa mono- than polycultures mixed with species. There was no significant effect aphid or predator abundance. Predator:prey ratios higher poly- monoculture. One predator, Nabis sp., selected for further study. A microcosm experiment indicated that is an effective both herbivores, suggested may enhance predation leafhoppers by Nabis. These results suggest limit populations protect from herbivory. The potential plants to increase herbivore movement vulnerability discussed.