3种不同类型棉田害虫与天敌时空动态变化

目的]为建立转基因棉田害虫的综合防治体系、合理保护和利用天敌和转基因棉的环境安全性评价提供一定的理论和实践依据。方法]对3种不同类型棉田(转双价棉、转Bt棉和常规棉田)害虫和天敌种群的时空动态进行研究。结果]3种类型棉田的害虫和捕食性天敌的种类基本相同,但数量差异较大。双价棉田害虫561头/百株,Bt棉田害虫589头/百株,常规棉田害虫1 018头/百株。不同时期害虫和天敌优势种类不同,害虫和天敌种群呈现有规律的时空变化,转双价棉田与转Bt棉田差异不显著,转基因棉田与常规棉田的差异达到显著水平。结论]转基因棉对害虫有明显抗性。群落特征指数分析表明,转基因棉田群落稳定性高于常规棉田,群落稳定性随棉花生长期呈现规律性变化。

Time-space Dynamic Change of Pests and Their Natural Enemies in Three Types of Cotton Fields

Objective] The purpose was to supply certain theoretical and practical basis for establishing the comprehensive control system against the pests in transgenic cotton field,reasonably protecting and utilizing the natural enemies and the environment safety evaluation of transgenic cotton.Method] The time-space dynamic research of pests and natural enemies populations in the three types of cotton fields(dual-toxin transgenic cotton,transgenic Bt cotton and conventional cotton).Result] The varieties of the pests and the predatory natural enemies in the three types of cotton fields were basically the same,but the quantity difference was bigger.The pest heads per 100 plants were 561 in the dual-toxin transgenic cotton cotton field,589 in the transgenic Bt cotton field and 1 018 in the conventional cotton field.The dominant species of the pests and the predatory natural enemies were different in various periods.The pests and natural enemies populations showed the regular time-space change. There was no significant difference between the dual-toxin transgenic cotton cotton field and the transgenic Bt cotton field,and the difference between the transgenic cotton field and the conventional cotton field achieved significant level.Conclusion] The transgenic cotton had obvious resistance against pest.The analysis on characteristic index of communities indicated that the community stability in transgenic cotton field was higher than that of conventional cotton field and the community stability showed the regular change along with the growth of cotton.