农药对桉树枝瘿姬小蜂幼虫的毒力测定

选取噻虫啉、吡虫啉、毒死蜱、噻虫嗪4种福建省林农广泛使用且内吸性强的药剂，采用对环境污染极小的树干注药法对桉树枝瘿姬小蜂虫瘿中的幼虫进行防治试验。结果表明，与前人采用喷雾法防治虫瘿内的幼虫相比，树干注药法防治效果更好。所选用的4种农药中，采用70%吡虫啉水分散粒剂的10倍液进行防治效果最好，施药18 d后校正死亡率达91.67％。4种药剂施药后2～10 d的桉树枝瘿姬小蜂幼虫的累积死亡率增幅都较10～20 d要大，且药剂稀释倍数越高，对幼虫的致死中时间越长。

Toxicity Test of Larvae of Leptocybe invasa Infected by Pesticides

As a strong and low toxicity systemic pesticide, thiacloprid, imidaclo-prid, chlorpyrifos and thiamethoxam are widely used in Fujian, for it is difficult to kill the larva and pupa of Leptocybe in-vasa in fields. We reached a conclusion that the new trunk injection method of the chemical control test of Leptocybe invasa was better than spraying ones, which were popular before, for a sound effect and low environmental pollution. All the 4 pesticides had a higher cumu-lative death rate in 2-10 days than in 10-20 days after testing. Among the 4 treatments, 70% imidacloprid water dis-persible granule diluted 10 times was of the most efficiency, whose corrected death rate was 91.67%, 18 days after in-jection.