沙冬青茎杆甲醇提取物对小菜蛾幼虫生长发育的影响

Effects of Methanol Extracts from Caudex of Ammopitanthus mongolicus L. on the Growth of the Larvae of Diamondback Moth,Plutella xylostella L.

室内测定了沙冬青茎杆甲醇提取物对小菜蛾幼虫生长发育的影响。结果表明,沙冬青茎杆甲醇提取物对小菜蛾幼虫生长发育具有明显的抑制作用。幼虫取食处理叶片后,体重增加较缓慢。而且随浓度的升高,这种体重抑制作用越强,最终导致高浓度处理中幼虫死亡较多。幼虫取食量、排粪量、食物近似消化率(AD)、食物利用率(ECI)、食物转化率(ECD)、相对生长率(RGR)、相对日均体重增长率(MRGR)均随提取物浓度的增加而降低。沙冬青茎杆甲醇提取物对小菜蛾幼虫历期的影响不明显,但使蛹期延长,幼虫死亡率升高。

Effects of methanol extracts from caudex of Ammopitanthus mongolicus L.on the growth of the larvae of diamondback moth,Plutella xylostella L.were investigated in laboratory.The results indicated that the extracts inhibited the growth of the larvae of diamondback moth distinctly.Weight gain of the larvae was very slowly after taking the leaf-discs treated with the methanol extracts.Such indexes as food intake,feces excreted,approximately digestive rate（AD）,eatable consuming rate（ECI）,eatable translating rate（ECD）,relative growth rate（RGR）,and mean relative growth rate（MRGR） decreased when concentration of methanol extracts from caudex of Ammopitanthus mongolicus L.increased.The concentration of the methanol extracts higher,the inhibitory effects more obviously and finally resulted in more death of larvae treated with higher concentrations.The lasting time of larvae of diamondback moth is affected unconspicuously,but the pupa time is postponed and the mortality rate of larvae is enhanced by the extracts.