香蕉园斜纹夜蛾幼虫的空间分布格局和抽样技术

本研究以Iwao直线回归方程和Taylor幂法则,结合3种常用聚集度指标,对香蕉园斜纹夜蛾低龄（1~2龄）、中龄（3~4龄）和高龄（5~6龄）3个龄期幼虫进行空间分布分析。结果表明：香蕉园斜纹夜蛾幼虫的空间分布型与幼虫龄期密切相关,且随着虫龄的增长,其聚集强度逐渐减弱;1~4龄幼虫空间分布格局为聚集分布,个体间相互吸引,其聚集强度随密度的增大而增大;5~6龄幼虫空间分布型由聚集分布逐渐趋向于均匀分布,且个体间存在相互排斥。在此基础上,以中龄幼虫为依据,建立了香蕉园斜纹夜蛾幼虫的最适理论抽样公式n=(t²/D²)(1.978/m+3.5119)和最佳序贯抽样公式$T(n) = n{m_0} pm 1.96sqrt {n(1.978{m_0} + 3.5119m_0^2}$。

Spatial Distribution Pattern and Sampling Technique of Spodoptera litura Larvae in Banana Parks

The Iwao linear regression equation and Taylor’s power law, three kinds of aggregation indexes were used to analyze the spatial distribution of Spodoptera litura larvae in banana parks in three stages: low age (1-2), middle age (3-4) and old age (5-6). The spatial distribution pattern of S. litura larvae was correlated with the larval age, and the aggregation intensity decreased with the increase of larval age. The spatial distribution pattern of 1-4 instar larvae was aggregation distribution, and the aggregation intensity increased with the increase of density. The spatial distribution pattern of 5-6 instar larvae gradually tended to uniform distribution from aggregation distribution, and there was mutual exclusion between individuals. The optimum theoretical sampling formula of S. litura larvae in banana parks was established n=(t²/D²)(1.978/m+3.5119) and the best sequential sampling formula $T(n) = n{m_0} pm 1.96sqrt {n(1.978{m_0} + 3.5119m_0^2}$.