Baek Sunghoon, Park Yong-Lak
Entomology Program, School of Natural Resources & the Environment, West Virginia University, Morgantown, WV 26505, USA.
Agro-Environment Research Institute, Epinet Co., Ltd., Anyang-si 14054, Republic of Korea.
Insects. 2024 Sep 28;15(10):751. doi: 10.3390/insects15100751.
Understanding the spatial patterns of insect pests and their associations with their environments is crucial for developing effective sampling and management plans. This study was conducted to identify optimal sampling units for the hemlock woolly adelgid, Annand (Hemiptera: Adelgidae) and to characterize its spatial distribution patterns in hemlock ( (L.) Carrière) stands in West Virginia, USA. To determine the optimal sampling unit, we randomly selected 24 branches from each of 46 -infested hemlock trees. The locations and number of ovisacs on each branch were recorded and the coefficient of variation was used to choose the optimal sampling units. To determine the spatial patterns of , each of the three 1-ha hemlock stands was divided into 100 grids, and ovisac counts were taken from the center of each grid. Semivariograms and spatial analysis by distance indices (SADIE) were used to analyze the spatial patterns of . In addition, various environmental and biological factors were measured to explore their spatial associations with . The results of this study revealed that the ovisacs exhibited spatial aggregation within branches, predominantly at the tips, and a 50 cm branch approximately 3 m above the ground was the optimal sampling unit. The spatial aggregation of in the hemlock stands was evident, and positive spatial associations were found between populations and factors including the aspect, tree diameter at breast height, and tree height. These findings offer valuable insights for the sampling and management of .
了解害虫的空间分布模式及其与环境的关系对于制定有效的抽样和管理计划至关重要。本研究旨在确定铁杉球蚜（Annand，半翅目：球蚜科）的最佳抽样单位，并描述其在美国西弗吉尼亚州铁杉（(L.) Carrière）林分中的空间分布模式。为了确定最佳抽样单位，我们从46棵受侵染的铁杉树上随机选取24个枝条。记录每个枝条上卵囊的位置和数量，并使用变异系数来选择最佳抽样单位。为了确定铁杉球蚜的空间分布模式，将三个1公顷的铁杉林分中的每一个都划分为100个网格，并从每个网格的中心统计卵囊数量。使用半变异函数和距离指数空间分析（SADIE）来分析铁杉球蚜的空间分布模式。此外，还测量了各种环境和生物因素，以探索它们与铁杉球蚜的空间关联。本研究结果表明，铁杉球蚜的卵囊在枝条内呈现空间聚集，主要集中在枝条顶端，地面以上约3米处的50厘米长枝条是最佳抽样单位。铁杉林分中铁杉球蚜的空间聚集明显，并且在种群与包括坡向、胸径和树高在内的因素之间发现了正空间关联。这些发现为铁杉球蚜的抽样和管理提供了有价值的见解。
