Cornell University, Department of Ecology and Evolutionary Biology, Corson Hall E149, Ithaca, New York 14853, USA.
Ecol Appl. 2011 Jul;21(5):1782-91. doi: 10.1890/10-0241.1.
Landscape composition affects ecosystems services, including agricultural pest management. However, relationships between land use and agricultural insects are not well understood, and many complexities remain to be explored. Here we examine whether nonagricultural landscapes can directly suppress agricultural pests, how multiple spatial scales of land use concurrently affect insect populations, and the relationships between regional land use and insect populations. We tracked densities of three specialist corn (Zea mays) pests (Ostrinia nubilalis, European corn borer; Diabrotica virgifera, western corn rootworm; Diabrotica barberi, northern corn rootworm), and two generalist predator lady beetles (Coleomegilla maculata and Propylea quatuordecimpunctata) in field corn and determined their relationships to agricultural land use at three spatial scales (field perimeter, 1-km, and 20-km radius areas). Pest densities were either higher (D. virgifera and D. barberi) or unchanged (O. nubilalis) in landscapes with more corn, while natural enemy densities were either lower (C. maculata) or unchanged (P. quatuordecimpunctata). Results for D. virgifera and D. barberi indicate that decreasing the area of preferred crop in the landscape can directly suppress specialist insect pests. Multiple scales of land use affected populations of D. virgifera and C. maculata, and D. virgifera populations showed strong relationships with regional, 20-km-scale land use. These results suggest that farm planning and government policies aimed at diversifying local and regional agricultural landscapes show promise for increasing biological control and directly suppressing agricultural pests.
景观组成会影响生态系统服务，包括农业害虫管理。然而，人们对土地利用与农业昆虫之间的关系了解甚少，仍有许多复杂性有待探索。在这里，我们研究了非农业景观是否可以直接抑制农业害虫，多种空间尺度的土地利用如何同时影响昆虫种群，以及区域土地利用与昆虫种群之间的关系。我们跟踪了三种玉米（Zea mays）害虫（Ostrinia nubilalis、欧洲玉米螟；Diabrotica virgifera、西部玉米根虫；Diabrotica barberi、北方玉米根虫）和两种普通捕食性瓢虫（Coleomegilla maculata 和 Propylea quatuordecimpunctata）在田间玉米中的密度，并确定了它们与三种空间尺度（田间周边、1 公里和 20 公里半径区）农业土地利用的关系。害虫密度在具有更多玉米的景观中更高（D. virgifera 和 D. barberi）或不变（O. nubilalis），而天敌密度更低（C. maculata）或不变（P. quatuordecimpunctata）。D. virgifera 和 D. barberi 的结果表明，减少景观中首选作物的面积可以直接抑制专食性昆虫害虫。多种尺度的土地利用影响了 D. virgifera 和 C. maculata 的种群，而 D. virgifera 的种群与 20 公里尺度的区域土地利用有很强的关系。这些结果表明，旨在使当地和区域农业景观多样化的农场规划和政府政策有望增加生物防治并直接抑制农业害虫。
