Biological pest control and yields depend on spatial and temporal crop cover dynamics

1. Modern agricultural landscapes are dynamic systems with interannually changing proportions of different crop types. However, the effects of spatiotemporal changes in crop area on crop yields and crop–herbivore–antagonist interactions have been rarely considered, in contrast to documented beneficial effects of semi-natural habitats on biological pest control at local and landscape scales. In this study, we examined how the proportion of oilseed rape (OSR) fields in a landscape and the annual increase or decrease in OSR cover due to crop rotation affect OSR herbivores, their natural enemies and crop yield. 2. During two study years, we examined the abundance of adult and larval pollen beetles, parasitism of pollen beetle larvae by a parasitic ichneumonid and crop yields (seed weight per plant) in the edge and centre of 36 OSR fields. The fields differed in the proportion of OSR in the surrounding landscape at 1-km radius and in the interannual change in the proportion of OSR from the p...

1. 现代农业景观是一类动态系统，其不同作物类型的占比会逐年发生变化。相较于已有研究证实的半自然生境在局地及景观尺度上对生物害虫防治的积极作用，作物面积的时空变化对作物产量以及作物-植食者-天敌互作的影响却极少受到关注。本研究旨在探讨景观中油菜（oilseed rape, OSR）田块占比，以及因作物轮作导致的油菜覆盖度年度增减，如何影响油菜植食者、其天敌以及作物产量。
2. 在为期两年的研究中，我们对36块油菜田的边缘与中心区域的成虫及幼虫花粉甲虫种群丰度、寄生姬蜂对花粉甲虫幼虫的寄生率，以及作物产量（单株种子重量）进行了调查。这些田块在周边1公里半径范围内的油菜占比、以及油菜占比的年度变化情况上均存在差异。