松瘿小卷蛾幼虫众数龄期的测定

Determination of Mode Stadia of Laspeyresia zebeana (Ratzeburg) Lavae

在自然条件下 ,对松瘿小卷蛾幼虫的发育进度作系统调查 ,然后通过常规的数学分析方法 ,确定幼虫的龄数和龄期。测定的结果是 ,松瘿小卷蛾幼虫共 7龄 ,各龄幼虫众数龄期分别为 :Ⅰ龄 38.2 5d ,Ⅱ龄 39.3d ,Ⅲ龄 32 .1d ,Ⅳ龄 35 .2 4d ,Ⅴ龄 2 4.7d ,Ⅵ龄 2 38.36d(含越冬时间 ) ,Ⅶ龄 2 9.8d。

After systematic investigation of development progress of Laspeyresia zebeana (Ratzeburg) larvae in natural condition, instars and stadia of lavae were determined through conventional mathematical analysis. The result reveals that the lavae of Laspeyresia zebeana (Ratzeburg) has seven instars altogether, and mode stadia of each instar is as follows: 1st instar 38.25 days, 2nd instar 39.3 days, 3rd instar 32.1 days, 4th instar 35.24 days, 5th instar 24.7 days, 6th instar 238.36 days (including overwinterring period) and 7th instar 29.8 days.