20种树木提取液对蔬菜害虫胃毒作用的研究

采集20种树木的叶、花和果实等材料，预处理后分步用石油醚、乙醇和水为溶剂，依次浸溃制备成树木提取液。分批对蔬菜害虫中的菜青虫和小菜蛾进行胃毒作用测定：(1)初选出乌桕、樟树等lO种树木对害虫毒效超过l0％的14种提取液；(2)试验结果显示，乙醇提取液对蔬菜害虫胃毒作用比石油醚提取液的效果好；(3)建议提高供试药液的浓度；(4)试验为进一步复筛试验提供了借鉴和准备工作。

A Study on Stomach Toxic Effect of Extracted Solution of 20 Tree Species on Vegetable Insects

The leaves, flowers, and fruits collected from 20 tree species were treated with ligron, ethanol, and water individually and made into extracted solutions. The stomach toxic effects of those extract solutions were tested on Pieris rapae and Plutella xylostella in vegetables. The test results were as follows: 1. The toxic efficacy of the extracted solution from 10 tree species, such as Sapium sebiferum,Cinnamomum camphora,and so on, was over 10%; 2. The toxic efficacy of the extracted solution prepared with ethanol was better than that of the solution prepared with ligron; 3. In order to improve the toxic efficacy, the paper advises to increase the concentration of the extracted solutions; 4. This experiment has provided reference and preparation for further studies.