Department of Entomology, University of Georgia, 1109 Experiment Street, Griffin, GA 30223, USA.
J Insect Sci. 2022 Sep 1;22(5). doi: 10.1093/jisesa/ieac050.
Arthropod predators are abundant in turfgrass systems, and they play an important role in managing pests. Understanding the vertical distribution of predation is critical to developing cultural strategies that enhance and conserve predatory services. However, little is known on how the predation is vertically distributed within the turfgrass canopy. Thus, the objective of this study was to determine the vertical distribution of predation within the turfgrass canopy. Clay models were used to emulate the general appearance of Noctuidae caterpillars, to estimate the predatory activity. The choice and no-choice experiments were conducted by placing clay models at 2.54, 5.08, and 7.62 cm from the thatch surface and denoted as lower, intermediate, and upper levels, respectively, within turfgrass canopy. The predator-mediated impressions, paired mark, scratch, deep cut mark, deep distortion, prick, dent, stacked surface impression, scooped mark, granulation, and U-shaped mark, were identified on clay models. The incidence and severity of impressions were significantly greater on clay models placed at the lower canopy level than on those placed at the intermediate and upper canopy levels in the choice and no-choice experiments (P < 0.05). Thus, predators are more likely to find their prey at the soil level. This information can be used to refine management strategies, such as mowing height and insecticide use for effectively managing soil-borne and foliar-feeding arthropod pests and beneficial arthropods.
节肢动物捕食者在草坪系统中大量存在，它们在害虫管理中起着重要作用。了解捕食的垂直分布对于制定增强和保护捕食服务的文化策略至关重要。然而，对于捕食在草坪冠层内是如何垂直分布的，人们知之甚少。因此，本研究的目的是确定捕食在草坪冠层内的垂直分布。粘土模型被用来模拟夜蛾科毛毛虫的一般外观，以估计捕食活动。选择和非选择实验通过将粘土模型放置在距草皮表面 2.54、5.08 和 7.62 厘米处，并分别表示为下层、中层和上层，在草坪冠层内进行。在粘土模型上识别出了捕食者介导的印象、配对标记、划痕、深切口标记、深变形、刺痕、凹痕、堆叠表面印象、舀痕、颗粒化和 U 形标记。在选择和非选择实验中，放置在下层冠层的粘土模型上的印象发生率和严重程度显著高于放置在中层和上层冠层的粘土模型（P<0.05）。因此，捕食者更有可能在土壤层找到它们的猎物。这些信息可用于改进管理策略，例如割草高度和杀虫剂的使用，以有效管理土壤传播和叶面取食的节肢动物害虫和有益节肢动物。
