Department of Agroecology, Aarhus University, Flakkebjerg Research Centre, Forgøsvej 1, DK4200, Slagelse, Denmark.
Dipartimento di Scienze Agrarie, Area Entomologia, Università di Bologna, Bologna, Italy.
Insect Sci. 2019 Jun;26(3):545-554. doi: 10.1111/1744-7917.12550. Epub 2017 Dec 27.
Humankind draws important benefits from large-scale ecological processes termed ecosystem services, yet the status of several of them is declining. Reliable monitoring methods are essential for tracking the status of ecosystem services. Predation is the mainstay of natural pest control, a key ecosystem service. We used green plasticine caterpillars to monitor predation pressure, and to obtain baseline data on predator activity in transgenic Bt versus non-Bt maize fields in Old and New World countries. Predation pressure was measured at ground and canopy levels using an identical, small-plot experimental design in four European countries (Denmark, Slovakia, Romania and Italy) and Argentina. Total predation rate in maize was 11.7%d (min. 7.2%d in Argentina, max. 29.0%d in Romania). Artificial caterpillars were attacked both by invertebrates (mostly chewing insects with 42.0% of the attack marks, and ants with 7.1%, but also predatory and parasitoid wasps, spiders and slugs), and vertebrates (small mammals 25.5%, and birds 20.2%). Total predation at ground level (15.7%d ) was significantly higher than in maize canopies (6.0%d ) in all countries, except Argentina. We found no significant differences between predator pressure in Bt versus non-Bt maize plots. The artificial caterpillar method provided comparable, quantitative data on predation intensity, and proved to be suitable for monitoring natural pest control. This method usefully expands the existing toolkit by directly measuring ecological function rather than structure.
人类从被称为生态系统服务的大规模生态过程中获得了重要的利益，但其中一些服务的状况正在下降。可靠的监测方法对于跟踪生态系统服务的状况至关重要。捕食是自然害虫控制的主要手段，也是一种关键的生态系统服务。我们使用绿色塑料毛毛虫来监测捕食压力，并在新旧世界国家的转基因 Bt 和非 Bt 玉米田中获得关于捕食者活动的基线数据。在四个欧洲国家（丹麦、斯洛伐克、罗马尼亚和意大利）和阿根廷，我们使用相同的小面积实验设计在地面和树冠层测量捕食压力。玉米中的总捕食率为 11.7%（阿根廷最低为 7.2%，罗马尼亚最高为 29.0%）。人工毛毛虫既受到无脊椎动物（主要是咀嚼昆虫，占攻击标记的 42.0%，蚂蚁占 7.1%，但也有捕食性和寄生性黄蜂、蜘蛛和鼻涕虫）的攻击，也受到脊椎动物（小型哺乳动物 25.5%，鸟类 20.2%）的攻击。在所有国家，除阿根廷外，地面的总捕食率（15.7%）明显高于玉米冠层（6.0%）。我们没有发现 Bt 和非 Bt 玉米田之间捕食压力有显著差异。人工毛毛虫方法提供了可比的、定量的捕食强度数据，并被证明适合监测自然害虫控制。这种方法通过直接测量生态功能而不是结构，有效地扩展了现有的工具包。
