金纹细蛾幼虫在陇东苹果树冠层的空间分布研究

为掌握金纹细蛾幼虫在苹果树冠层不同部位的发生规律，为科学防治提供技术支持。以长富2号10年生富士苹果园为研究对象，通过对不同时期金纹细蛾幼虫发生规律、树冠分布特征和集聚性分析，研究了陇东金纹细蛾幼虫在苹果树冠上的空间分布结构。结果发现，金纹细蛾幼虫1 a发生5代。在世代重叠现象和苹果生长期药剂防控的双重影响下，第2代以后各世代之间未出现明显的高峰，在9月上旬之前幼虫数量虽有增长，但增长非常缓慢，而进入9月下旬之后越冬代数量成倍数骤增。从幼虫在树冠上的空间分布看，存在东向和北向＞南向和西向、下部 ＞ 上部、内膛 ＞ 外围的趋势，但是在统计学上却没有显著差异；幼虫在苹果树冠中的分布呈一定的聚集性分布，但聚集度比较小。在前期防控的基础上，加强9月下旬以后的防控，是减少翌年虫源的关键。药剂防控中，在保证树冠全方位防控的同时，树冠下部、内膛、南向和西向为重点防控的空间部位。

Spatial Distribution of the Larvae of Lithocolletis ringoniella Mats in the Canopy of Apple Trees in Eastern Gansu

To understand the occurrence regularity of the larvae of Lithocolletis ringoniella Mats in different parts of apple tree canopy and to provide the technical support for the scientific prevention and control, 10-year-old Fuji apple orchards were taken as the research object in this study, by analyzing the occurrence regularity, canopy distribution characteristics and agglomeration of larvae of Lithocolletis ringoniella Mats in different periods, the spatial distribution structure of larvae in the apple tree canopy in Longdong area was studied. The results showed that the larvae had five generations a year. Since the growth period of apples is affected by intergenerational overlap and pesticide control, after 2 generations, there was no obvious peak of occurrence between generations. Before the beginning of September, although the number of larvae increased, the growth was very slow, and the number of overwintering generations increased exponentially by the end of September. From the spatial distribution of larvae in the canopy, a trend of east and north > south and west, lower > upper, and inner hall > outer was detected, but no statistically significant difference existed. The distribution of larvae in apple canopy showed a certain aggregation distribution, but the aggregation degree was relatively small. Therefore, it was suggested that on the basis of the previous prevention and control, strengthening the prevention and control after late September was the key to reduce the source of insects in the following year. In terms of the chemical prevention and control, while ensuring the comprehensive prevention and control of the tree canopy, the lower part of the tree canopy, the inner hall, the south, and the west are the key space parts for prevention and control.