Abstract Ecosystem can offer regulating services to change biodiversity patterns and ecological processes and then affect the prevalence of crop pests. Biological pest control could serve as an environmentally friendly ecological control service to suppress crop pests and decrease pesticide use by maintaining or increasing natural enemies. However, few study focus on the explicit process of natural enemies, pest dynamics, quantitative assessment and maintaining mechanism of ecological control service in multi-crop farmland landscape system for the whole crops growing cycle. Here, an experimental model of rotation-intercropping ecosystem via wheat-maize-cotton was planned for three consecutive years to response above questions. Our result found the rotation-intercropping ecosystem help to increase the abundances of the dominant natural enemy, Propylea japonica adults and then promoted aphid reduction in center cotton plots. In crops growing cycle, many predators maintained in wheat from Mid-April to late May, then the predator moved to inhabit in maize before wheat harvest during early June. During the intercropping period of maize and cotton, the predator would prefer to back and forth inhabit in maize and travel to cotton to actively prey on cotton pests. Quantitative evaluation of pest control based on a new built method of Ecological Control Service Index (ESI) found that crop diversity has highly efficient control function in rotation-intercropping ecosystem. The values of ESI at the peak of cotton aphids on center cotton plots were 0.80 in 2012, 0.31 in 2013 and 0.61 in 2014, respectively. The sustainably available prey resources in multi-crops ecosystem and maize as crop habitat with conditions of relative low temperature (28.5℃) and high humidity (68.3 %) are beneficial to maintain the predator natural enemy and ecological control service. Thus, our results suggest that giving full play to the ecological control service of crop diversity in rotation-intercropping ecosystem is beneficial to decrease crop pests and pesticide use, especially under the aggravating agricultural intensification. These findings support growing efforts from landowner, field manager and policy-makers to promote this ecosystem service via designing crops patterns and adjusting crops growing circle in regional agroecosystem.

中文翻译：

---

小麦-玉米-棉花轮作间作生态系统中捕食性天敌的生态控制服务及其维持机制

摘要 生态系统可以提供调节服务，改变生物多样性格局和生态过程，进而影响农作物病虫害的流行。生物害虫防治可以作为一种环境友好的生态防治服务，通过维持或增加天敌来抑制作物害虫和减少农药的使用。然而，很少有研究关注多作物农田景观系统整个作物生长周期的天敌显性过程、病虫害动态、生态控制服务的定量评估和维持机制。在这里，连续三年规划了小麦-玉米-棉花轮作间作生态系统的实验模型来回答上述问题。我们的结果发现轮作间作生态系统有助于增加主要天敌的丰度，Propylea japonica 成虫，然后促进中心棉田的蚜虫减少。在作物生长周期中，4 月中旬至 5 月下旬，许多捕食者在小麦中生存，然后在 6 月初小麦收获前，捕食者转移到玉米中栖息。在玉米和棉花间作期间，捕食者更喜欢在玉米中来回栖息，并前往棉花积极捕食棉花害虫。基于新建立的生态控制服务指数（ESI）方法的病虫害防治定量评价发现，作物多样性在轮作间作生态系统中具有高效的控制功能。2012年、2013年、2014年、2012年、2013年、2014年，棉蚜高峰期ESI值分别为0.80、0.61和0.61。多作物生态系统和玉米作为作物栖息地，在相对低温（28.5℃）和高湿度（68.3%）条件下可持续可用的猎物资源有利于维持捕食者天敌和生态控制服务。因此，我们的研究结果表明，在轮作间作生态系统中充分发挥作物多样性的生态控制服务有利于减少作物病虫害和农药的使用，尤其是在农业集约化加剧的情况下。这些发现支持土地所有者、田间管理者和政策制定者通过设计作物模式和调整区域农​​业生态系统中的作物生长圈来促进这种生态系统服务的努力。3%)有利于维持捕食天敌和生态控制服务。因此，我们的研究结果表明，在轮作间作生态系统中充分发挥作物多样性的生态控制服务有利于减少作物病虫害和农药的使用，尤其是在农业集约化加剧的情况下。这些发现支持土地所有者、田间管理者和政策制定者通过设计作物模式和调整区域农​​业生态系统中的作物生长圈来促进这种生态系统服务的努力。3%)有利于维持捕食天敌和生态控制服务。因此，我们的研究结果表明，在轮作间作生态系统中充分发挥作物多样性的生态控制服务有利于减少作物病虫害和农药的使用，尤其是在农业集约化加剧的情况下。这些发现支持土地所有者、田间管理者和政策制定者通过设计作物模式和调整区域农​​业生态系统中的作物生长圈来促进这种生态系统服务的努力。