Abstract: With 70% imidacloprid, 40% chlorpyrifos，25% thiamethoxam and the mixture pesticides were carried out in a dilution ratio of 5×, 10× and 20× concentration to control Leptocybe invasa larvae by the trunk injection method, respectively. The results showed that after 30 d, the corrected mortality are different with same concentration of different pesticides, and the corrected mortality is extremely significant . The 5× concentration is the most effects, and the corrected mortality is 81.63% in 30 d. The death ratio of Leptocybe invasa larvae is the largest increase in 5～10 d, and over 10 d it is slower. The higher concentration of pesticides , the median lethal time is fast for the Leptocybe invasa larvae.

Key words: Leptocybe invasa, eucalyptus galls, chemical control test, median lethal time

摘要： 选用70%吡虫啉水分散粒剂、40%毒死蜱乳油、25%噻虫嗪水分散粒剂以及这3种农药的混配剂，分别稀释成5、10、20倍液，采用注干法对桉树枝瘿姬小蜂幼虫进行林间药效试验。试验表明，施药30 d后，相同浓度的不同药剂对桉树枝瘿姬小蜂幼虫的校正死亡率则存在极显著差异。混配剂5倍液的防治效果最好，在30 d内对桉树枝瘿姬小蜂幼虫的校正死亡率为81.63%。施药后5～10 d，桉树枝瘿姬小蜂幼虫的死亡率增长速度最快；施药10 d后，死亡率的增长速度明显变缓。同一种药剂的浓度越高，对桉树枝瘿姬小蜂幼虫的致死时间越短。

关键词: 桉树枝瘿姬小蜂, 虫瘿, 化学防治试验, 致死中时间