Exploring soybean integrated pest management in a changing agricultural environment: the impacts of decreasing ecosystem services, invasive species and specialty cultivars.

摘要

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) is a recently invasive pest to North America. Integrated pest management strategies exist for minimizing the impact of the soybean aphid on yield. These strategies were developed from field-based research conducted under the environmental conditions of the time and using commodity soybean plants. The increased use of broad spectrum insecticides and the increased simplification of the landscape along with the release of altered fatty acid soybean cultivars have led to changes in the agricultural environment. How these changes affect soybean aphid population dynamics and interactions between the soybean aphid and other pests is investigated. The first objective was to determine how reduced natural enemy services may impact soybean aphid population growth between the economic threshold and economic injury level. The second objective was to determine how the soybean aphid could indirectly interact with the soybean cyst nematode, Heterodera glycines Ichinhoe and the brown stem rot fungus, Cadophora gregata Harrington and McNew. The third and fourth objectives were to determine the effect of altered fatty acid cultivars on soybean pests and pathogens. Objective four quantified the effect of these cultivars on the performance of the soybean aphid, soybean cyst nematode and brown stem rot. Objective five addressed how the alterations in fatty acid synthesis pathways present in these cultivars may affect plant volatile emissions and the downstream impact this has on host plant selection by the bean leaf beetle, Cerotoma trifurcata Forster (Coleoptera: Chrysomelidae).