Parajulee M N, Shrestha R B, Leser J F
Texas Agricultural Experiment Station, Lubbock 79403, USA.
J Econ Entomol. 2006 Apr;99(2):568-77. doi: 10.1603/0022-0493-99.2.568.
A 2-yr field study was conducted to examine the effectiveness of two sampling methods (visual and plant washing techniques) for western flower thrips, Frankliniella occidentalis (Pergande), and five sampling methods (visual, beat bucket, drop cloth, sweep net, and vacuum) for cotton fleahopper, Pseudatomoscelis seriatus (Reuter), in Texas cotton, Gossypium hirsutum (L.), and to develop sequential sampling plans for each pest. The plant washing technique gave similar results to the visual method in detecting adult thrips, but the washing technique detected significantly higher number of thrips larvae compared with the visual sampling. Visual sampling detected the highest number of fleahoppers followed by beat bucket, drop cloth, vacuum, and sweep net sampling, with no significant difference in catch efficiency between vacuum and sweep net methods. However, based on fixed precision cost reliability, the sweep net sampling was the most cost-effective method followed by vacuum, beat bucket, drop cloth, and visual sampling. Taylor's Power Law analysis revealed that the field dispersion patterns of both thrips and fleahoppers were aggregated throughout the crop growing season. For thrips management decision based on visual sampling (0.25 precision), 15 plants were estimated to be the minimum sample size when the estimated population density was one thrips per plant, whereas the minimum sample size was nine plants when thrips density approached 10 thrips per plant. The minimum visual sample size for cotton fleahoppers was 16 plants when the density was one fleahopper per plant, but the sample size decreased rapidly with an increase in fleahopper density, requiring only four plants to be sampled when the density was 10 fleahoppers per plant. Sequential sampling plans were developed and validated with independent data for both thrips and cotton fleahoppers.
开展了一项为期两年的田间研究，以检验两种抽样方法（目视法和植株冲洗技术）对西花蓟马Frankliniella occidentalis (Pergande)的有效性，以及五种抽样方法（目视法、拍桶法、滴布法、扫网法和真空法）对棉盲蝽Pseudatomoscelis seriatus (Reuter)在德克萨斯州棉花Gossypium hirsutum (L.)上的有效性，并为每种害虫制定序贯抽样计划。在检测西花蓟马成虫方面，植株冲洗技术与目视法的结果相似，但与目视抽样相比，冲洗技术检测到的蓟马幼虫数量显著更多。目视抽样检测到的棉盲蝽数量最多，其次是拍桶法、滴布法、真空法和扫网法，真空法和扫网法的捕获效率没有显著差异。然而，基于固定精度成本可靠性，扫网抽样是最具成本效益的方法，其次是真空法、拍桶法、滴布法和目视抽样。泰勒幂法则分析表明，在整个作物生长季节，蓟马和棉盲蝽的田间分布模式都是聚集型的。对于基于目视抽样（精度为0.25）的蓟马管理决策，当估计种群密度为每株植物有1头蓟马时，估计最小样本量为15株植物，而当蓟马密度接近每株植物10头蓟马时，最小样本量为9株植物。当棉盲蝽密度为每株植物1头时，目视抽样的最小样本量为16株植物，但样本量随着棉盲蝽密度的增加而迅速减少，当密度为每株植物10头棉盲蝽时，只需要对4株植物进行抽样。为蓟马和棉盲蝽制定了序贯抽样计划，并用独立数据进行了验证。
