粘虫生物学特性及生命表研究

STUDIES ON THE BIOLOGICAL CHARICTERISTICS AND LIFE TABLE OF THE ARMYWIRM [Leitcania separata (Walker)]

以万源县第二代粘虫为研究对象,依据颜色变化将卵分为4级;依据复眼色泽、体色和翅芽变化将蛹分为5级.确定了头宽值的幼虫分龄标准,并认为粪粒大小和体长也可作为分龄的参考标准.建立了卵块大小(X)与含卵量(Y)的关系Y=20.38+4.261 4X.讨论了各虫态的习性、历期及发育进度等生物学特性.建立了实验种群特定年龄生命表.世代死亡率为82%,卵、幼虫、蛹和成虫期的死亡率分别为8%,55.54%,19.75和50.61%.种群增长指数I=0.423 7,分析了种群数量减少的原因.

The study on the second generation of the army worm Lfuwiui sepirHtn (Walker), had been carried ou' in Wan Yuan County. Sichuan Province during 1987-- 1989. The developmental period of egg was divided into four grades according to the variation of its colour and that of pupa was divided into five grades accoring to the variations of the colour of eye. body and wing gemma. The criterion of head width to divide instar of larva was given and criteria of both excrement grain si^e and txxly length were also discussed. The biological characters including behavior, developmental period and so on were presented. The relationship model between the si/e of egg-clump ( X ) and egg containing quantity (Y), i. e. Y=20. 38+1. 26! X, and the age-specific life table of experimental population were established. The mortalities of all the generations, egg, larva, pupa and adult were 82 '-A, 8 % . 55. 5'1 % , I 9. 75 % and 50. 6 ! % respectively. The population increase index I was 0. 123 7. and the causes of population quantity decrease was also analysed.