Knutson Allen E, Muegge Mark A, Wilson L T, Naranjo Steve E
Texas A&M AgriLife Research and Extension Center, Dallas, TX 75252-6502, USA.
J Econ Entomol. 2008 Aug;101(4):1501-9. doi: 10.1603/0022-0493(2008)101[1501:eosmad]2.0.co;2.
The cost-reliability of five sampling methods (visual search, drop cloth, beat bucket, shake bucket, and sweep net) was determined for four groups of predatory arthropods on cotton plants in Texas. The beat bucket sample method was the most cost-reliable sampling method for Orius adults, and the beat bucket and drop cloth were the most cost-reliable methods for Orius nymphs. The drop cloth and beat bucket were the most cost-reliable methods for sampling spiders. For sampling adult Coccinellidae, the sweep net and the beat bucket were the most cost-reliable. The visual sample method was the least cost-reliable method for Orius adults and nymphs and spiders. No one sampling method was identified as the optimum method for all four predator groups. However, the relative cost-reliability of the beat bucket method ranked first or second among the five sampling methods and this method was chosen for further evaluation in field studies in Texas and Arizona. The relative cost-reliability of 1-, 3-, 5-, and 10-plants per beat bucket sample varied with predator group, but multiple plant sample units were equal to or more cost-reliable than the one plant sample unit. Fixed sample plans for the beat bucket method were developed for Orius adults, Orius nymphs, spiders, and adult Coccinellidae, and the sum of these groups using the 3-, 5-, and 10-plant sample unit sizes. The greater cost-reliability of the beat bucket sampling method and its ease of use is of particular advantage in assessing predator densities in a commercial cotton field monitoring program.
在得克萨斯州的棉花植株上，针对四类捕食性节肢动物，测定了五种采样方法（目视搜索、铺布法、拍桶法、摇桶法和扫网法）的成本可靠性。对于成年小花蝽，拍桶采样法是成本可靠性最高的采样方法；对于小花蝽若虫，拍桶法和铺布法是成本可靠性最高的方法。铺布法和拍桶法是采样蜘蛛的成本可靠性最高的方法。对于采样成年瓢虫科昆虫，扫网法和拍桶法是成本可靠性最高的方法。目视采样法对于成年小花蝽、小花蝽若虫和蜘蛛而言，是成本可靠性最低的方法。没有一种采样方法被确定为适用于所有四类捕食者群体的最佳方法。然而，拍桶法的相对成本可靠性在这五种采样方法中排名第一或第二，因此该方法被选用于在得克萨斯州和亚利桑那州进行的田间研究的进一步评估。每拍桶样本中1株、3株、5株和10株植物的相对成本可靠性因捕食者群体而异，但多个植物样本单位的成本可靠性等于或高于单株植物样本单位。针对成年小花蝽、小花蝽若虫、蜘蛛和成年瓢虫科昆虫，以及使用3株、5株和10株植物样本单位大小的这些群体的总和，制定了拍桶法的固定采样计划。拍桶采样法更高的成本可靠性及其易用性，在商业棉田监测项目中评估捕食者密度方面具有特别的优势。
