Abstract:

Objective To study the effect of mosquito age on the pyrethroid resistance and P450 monooxygenase activity in Anopheles sinensis in Huainan City，Anhui Province，China，as well as the molecular mechanism of pyrethroid resistance. Meth? ods Anopheles mosquito larvae were collected in fields，and were emerged to adults. Then the pyrethroid resistance and P450 monooxygenase activity of female mosquitoes were detected 1，3，6，9，12，15 d and 20 d after emergence. Meanwhile，the resis? tance level and P450 monooxygenase activity of the sensitive mosquitoes in lab were detected as the control group. Results Both curves of pyrethroid resistance and P450 monooxygenase activity changes with the mosquito age presented unsymmetrically re? versed“U”type. At 1 d after emergence，the resistance level and P450 monooxygenase activity were lower，and then they in? creased quickly. When 3?9 d after emergence，the resistance level and P450 monooxygenase activity rose to the highest level，and entered into plateau，then declined gradually. Compared to the sensitive mosquitoes in lab，the P450 monooxygenase activity of those in the field was higher at 3?12 d after emergence，but lower at 1 d after emergence，and at 15 and 20 d after emergence，they were almost equal to each other. Conclusion The mosquito age is a confounding factor in the detection of resistance level and en? zyme activity. The promotion of activity of P450 monooxygenase may be one of the reasons of the resistance. Using female adults with different ages in the field as study subjects may underestimate the real resistance level of mosquitoes，and mislead the use of insecticides.

Key words: Anopheles sinensis； Resistance； Mosquito age； P450 monooxygenase

摘要：

目的 目的 研究蚊龄对安徽淮南中华按蚊溴氰菊酯抗性和P450单加氧酶活性的影响以及其抗性产生的分子机制。方法 方法 在安徽省淮南市现场采集中华按蚊幼虫， 饲养羽化， 分别在雌蚊羽化后1、 3、 6、 9、 12、 15 d和20 d时， 测定其抗药性和P450单加氧酶活性， 并以实验室敏感蚊作为对照组， 比较二者抗药性和P450单加氧酶活性。结果 结果 随蚊龄增长， 安徽中华按蚊溴氰菊酯抗性和P450单加氧酶活性曲线均呈不对称倒U形变化。1 d龄时， 抗性和P450单加氧酶活性较低； 其后迅速增加， 至3～9 d时达到顶峰， 进入平台期； 随后， 抗性和P450单加氧酶活性均逐渐降低。3～12 d龄蚊虫P450单加氧酶活性高于敏感蚊， 15 d与20 d龄蚊虫与敏感蚊类似， 1 d龄蚊虫则低于敏感蚊。 结论 结论 蚊龄是蚊虫抗性和酶活性检测的混杂因素。P450单加氧酶活性增强可能是当地中华按蚊溴氰菊酯抗性产生的原因之一。采用蚊龄不一致的现场蚊作为测试对象可能会低估其抗性水平， 误导杀虫剂的使用。

关键词: 中华按蚊； 抗药性； 蚊龄； P450单加氧酶