春甘蓝田小菜蛾种群动态研究

在田间系统调查的基础上，采用模糊聚类分析和时间动态空间生态位宽度与种群密度关系分析方法，研究了合肥地区春甘蓝田小菜蛾的种群动态，旨在为小菜蛾的科学治理提供依据。研究结果表明，春甘蓝田小菜蛾种群动态可分为3 个发展阶段——点片发生阶段（低密度、高聚块）、扩张发生阶段（中密度、低聚块）和猖獗发生阶段（高密度、低聚块）。小菜蛾对春甘蓝的为害情况比较复杂，种群密度较低时主要为害甘蓝心叶；随着甘蓝的生长和小菜蛾种群密度的上升逐渐向内层叶和外层叶扩展，最终导致甘蓝全株受害。小菜蛾种群处于点片发生阶段时是春甘蓝田小菜蛾防治的关键时期。

Population Dynamics of Plutella xylostella (L.) in Spring Cabbage Fields

Based on a systematic field investigation, the methods of the fuzzy cluster analysis and the relationship analysis of temporal-dynamic spatial niche breadth with population density were used to study the population dynamics of Plutella xylostella (L.) in spring cabbage fields in Hefei, in order to provide basis for scientific management of diamondback moth. The research results showed that the population dynamics of Plutella xylostella (L.) in spring cabbage fields could be divided into three development periods: dot and patch occurrence period (low population density and high patchiness), expansive occurrence period (medium population density and low patchiness) and rampant occurrence period (high population density and low patchiness). The damage of diamondback moth to spring cabbage was quite complicated. Diamondback moth attacked the heart leaves of cabbage mainly in low population density and dispersed gradually to inner and outer leaves of cabbage with the growth of cabbage and the rise of its population density and led to the damage of whole cabbage plant eventually. The dot and patch occurrence period of diamondback moth population in spring cabbage fields was the critical control time.