Gutierrez-Coarite Rosemary, Pulakkatu-Thodi Ishakh, Wright Mark G
Entomology Section, Department of Plant and Environmental Protection Sciences, Komohana Research and Extension Center, Hilo, HI.
Entomology Section, Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Gilmore Hall, Honolulu, HI.
Environ Entomol. 2019 Feb 13;48(1):219-226. doi: 10.1093/ee/nvy160.
The macadamia felted coccid, Eriococcus ironsidei (Williams) is an invasive pest of macadamia orchards that causes severe damage to the trees and reduces nut yield in Hawaii. Their feeding results in distortion and stunting of new growth, and with high population densities, dieback of entire branches may result. Ten macadamia orchards were sampled on the Hawaii island over a period of 18 mo to characterize the dispersion of the pest in the field, and to use those data as the basis for the development of a binomial sampling plan. Analyses based on Taylor's Power Law and Iwao's mean crowding index indicated an aggregated pattern of dispersion of the pest in the field. Curvilinear relationships between mean crawler density and the proportion of infested trees based on four tally thresholds (crawlers per unit area, T > 0, 5, 10, 20) were plotted. Results showed that a tally threshold T > 10 was the best predictor to model mean crawler density. Binomial sequential sampling plans based on three critical proportions of trees infested (0.40, 0.60, and 0.80) were developed. The adoption of a binomial sequential sampling plan for use in decision making can contribute to improve the management of E. ironsidei and optimize the number of samples needed to make decisions to control this pest.
澳洲坚果毡蚧，即艾氏毡蚧（Williams），是澳洲坚果果园的一种入侵性害虫，在夏威夷会对树木造成严重损害并降低坚果产量。它们的取食会导致新梢扭曲和发育不良，在虫口密度高时，可能会导致整枝枯死。在18个月的时间里，对夏威夷岛上的10个澳洲坚果果园进行了采样，以描述该害虫在田间的分布情况，并将这些数据作为制定二项式抽样计划的基础。基于泰勒幂法则和岩尾平均拥挤指数的分析表明，该害虫在田间呈聚集分布模式。根据四个计数阈值（每单位面积的若虫数，T > 0、5、10、20）绘制了平均若虫密度与受害树木比例之间的曲线关系。结果表明，计数阈值T > 10是模拟平均若虫密度的最佳预测指标。制定了基于三个受害树木临界比例（0.40、0.60和0.80）的二项式序贯抽样计划。采用二项式序贯抽样计划进行决策有助于改善对艾氏毡蚧的管理，并优化控制该害虫决策所需的样本数量。
