棉铃虫发生程度与降雨量关系的研究(英文)

Studies on the Relationship between Occurrence Degree of Cotton Bollworm and Rainfall

棉铃虫是鹿邑县植棉区常发性主要害虫，一年发生4～5代，危害棉花的主要是二、三、四代。棉铃虫最适生活温度为25～28℃。适宜温度下，温度越低，生长周期越长；温度越高，各代发育时间越短。由于棉铃虫受多食性的影响，它可以寄生在若干种植物上，一旦气候条件适宜，则生长发育速度加快，易导致代次增加和种群大暴发。笔者从适宜气候条件的角度研究棉铃虫大发生的原因，以期为棉铃虫的有效防治提供理论依据。

[ Objective ] The aim of the study is to investigate the factors causing the outbreak of cotton bollworm and to provide effective measures for controlling cotton bollworm. [ Method] Based on the analysis of the data about insect and weather situation in Luyi County in 32 years, the meteorological, prediction model was established for monitoring the quarterly or monthly occurrence trend of cotton bollworm. [Result] The cotton boillworm occurred slightly in the years with rainfalls of 3 months over 500 nm and severely in the years with rainfalls of 3 months： less than 400 rim. The results of correlation analysis show that annual occurrence degrees of cotton bollworm and occurrence degrees of 4^th generation of cotton bollworm are extremely negatively correlated with rainfall during June - August; the occurrence degrees of 3^rd and 4^th generations of cotton bollworm are also extremely negatively correlated with rainfall in July. [ Conclusion] The occurrence of cotton bollworm in field is heavily influenced by rainfall in at its occurrence stage; moreover, the rainfall during June - August is the decisive factors influencing the occurrence of cotton bollworm.