Characteristics of the Aggregation Pattern of the Striped Rice Borer(Chilo suppressalis(Walker) during the Larval Stage

이화명나방유충(幼蟲)의 공간분포특성(空間分布特性)

  • Ryoo, Mun-Il (Dept. of Plant Protection, College of Agriculture, Korea University) ;
  • Lee, Moon-Hong (Institute of Agricultural Sciences)
  • 유문일 (고려대학교 농과대학 식물보호학과) ;
  • 이문홍 (농업기술연구소)
  • Published : 1985.04.30

Abstract

The data on the striped rice, borer populations, collected in the four years from 1973 to 1976, was reanalyzed to study the characteristics in the aggregation pattern of the insect larvae in the paddy fields. The distribution pattern of the larvae was well fitted to the negative binomial model in both the first and the second generation. With reference to the Green's coefficient of dispersion estimated, the aggregation of the larvae was categorized into three phases: initial high aggregation, changing, and dispersed stable phase. Except the changing phase, each phase in each generation could be defined by a common k. The phase-change was initiated by the larval dispersal between hills of the rice plants: the larvae of the third stage and those of the fifth stage, for the first and second generation, respectively. The characteristics of the aggregation pattern were stable in the second generation. In the first genaration, the pattern was more or less variable, indicating that the life system of the insect in the first generation was more susceptible to the variations of the external physical factors than that in the second generation.

Keywords