棉铃虫寄主间“源—库”关系及棉田防治压力值研究

STUDIES ON THE SOURCE-SINK RELATIONSHIP AMONG HOST PLANTS OF COTTON BOLLWORM AND CONTROL PRESSURE ON COTTON

通过江苏淮南、淮北棉区棉铃虫寄主种类调查、适合性程度测定与不同代次棉铃虫寄主演替规律研究,明确了棉铃虫在棉区内众多寄主间“源—库”转换关系主要受寄主本身适合性程度与面积比例的影响。而棉铃虫在适宜与较适宜栽培寄主上的消长动态基本代表了整个棉区棉铃虫寄主间“源—库”转换关系。为量化寄主间“源—库”关系与优化棉铃虫防治决策,建立了寄主适合性综合指数、区域性综合容量指数与棉田棉铃虫防治压力值分析方法与估测模型。测定结果表明,淮北棉区棉田2～4代棉铃虫防治压力值分别为78.02％、22.04％与22.34％;而淮南棉区棉田2～4代棉铃虫压力值分别为64.02％、57.69％与84.10％。

Based on the extensive investigations of host plant species and their fitnesses to cotton bollworm (CBW) Helicoverpa armigera (Hubner) as well as the succession regularity of host importance from 1st to 4th generation of CBW in Northern and Southern Huaihe River Valley Cotton Regions, Jiangsu Province, it was clarified that in a cotton area, the transformation of source-sink relationship among various host plants depended on their fitness level and proportion of cultivated acreage, and the dynamics of CBW populations on most suitable and suitable cultivated host plants had reflected the general situation of source-sink relationship transformation of all of its host plants in whole cotton area. Models for calculating the fitness-acreage index, area capacity index of host plant and control pressure on cotton against CBW were proposed to quantify the source-sink relationship among host plants and optimize the control decision making of CBW. The results showed that the control pressure values for 2nd, 3rd and 4th CBW generations in Northern and Southern Huaihe River Valley Cotton Regions were 78.02%, 22.04% and 22.34%, and 64.02%, 57.69% and 84. 10%, respectively.