Yan Wen-Tao, Qiu Gui-Sheng, Zhou Yu-Shu, Zhang Huai-Jiang, Chen Han-Jie, Zhang Ping, Liu Chi-Lin, Zheng Yun-Cheng
Research Institute of Pomology, Chinese Academy of Agricultural Sciences, Xingcheng 125100, Liaoning, China.
Ying Yong Sheng Tai Xue Bao. 2011 Nov;22(11):3053-9.
Panonychus ulmi Koch is one of the important pest insects of apple production in China. To clarify the spatiotemporal dynamics of P. ulmi on the apple tree crowns in an apple orchard of Liaoning, Northeast China, an investigation with random sampling was conducted on the pest mite number at each direction and each layer of the crowns in the whole growth season from May to November 2007. The spatial distribution pattern and time series dynamics of P. ulmi were analyzed by calculating the indices of aggregation and using the parameters of Iwao model. In the early and mid growth periods of apple tree, P. ulmi within whole crown fitted negative binomial distribution, presented an aggregated pattern, and its fundamental component was the group composed of several individuals that attracted each other. The aggregation intensity showed a negative fluctuation with population density, namely, high population density but low patchiness density, and low population density but high patchiness density, and there existed definite differences at different crown directions and layers, i. e., the patchiness density was the highest in south direction and the lowest in west direction, and was higher in mid and lower layers than in upper layer, and in inner layer than in outer layer.
苹果全爪螨（Panonychus ulmi Koch）是中国苹果生产中的重要害虫之一。为阐明中国东北辽宁省某苹果园苹果树冠上苹果全爪螨的时空动态，于2007年5月至11月的整个生长季节，对树冠各方向和各层的害螨数量进行了随机抽样调查。通过计算聚集指标并利用Iwao模型参数，分析了苹果全爪螨的空间分布格局和时间序列动态。在苹果树生长的前期和中期，全树冠内的苹果全爪螨符合负二项分布，呈聚集型分布，其基本成分是由相互吸引的若干个体组成的群体。聚集强度随种群密度呈负波动，即种群密度高时斑块密度低，种群密度低时斑块密度高，且在树冠不同方向和层次存在一定差异，即斑块密度在南向最高，西向最低，中下层高于上层，内层高于外层。
