湖北恩施烟夜蛾幼虫田间分布格局的地统计学分析

Geostatistical analysis on distribution pattern of the tobacco budworm larva in Enshi,Hubei,China

烟夜蛾以幼虫取食烟叶,给烟叶生产带来巨大损失.运用地统计学的方法,研究了湖北恩施烟区烟夜蛾幼虫的空间结构和发生动态.结果表明:恩施烟区烟夜蛾幼虫在烟叶移栽后40 d开始为害,至烟叶成熟前期达到高峰;球形-指数套合模型为烟夜蛾幼虫田间分布的主要模型,属聚集分布;空间变异度C/(C0+C)均大于0.75,说明其结构性变异较大,随机性变异较小;烟夜蛾幼虫在烟叶旺长期进行了较大迁移,之后其数量趋于稳定,烟叶成熟期尤其稳定.

Tobacco budworm （Helicoverpa assulta） larvae feed on tobacco leaves （Nicotiana sp. ）, resulting in significant loss in tobacco production. Geostatistical method was used to analyze H. assulta spatial patterns and dynamics in this paper. The results showed that, H. assulta larvae appeared 40 days after the tobacco plants transplanting, and reached its peak at the early-mature period. The nested spherical and exponential model was the major model for tobacco budworm larva in the field, suggesting its aggregated distribution. The spatial variability C/（ CO ＋C） was larger than 0.75, which indicated H. assulta larva had wider structural variation and narrower random varia- tion. There was a massive migration of tobacco budworm larva in the fast-growing stage of tobacco. Its quantity became stable after that, especiaXly at the mature stage of tobacco.