Understanding the mechanisms of insecticide resistance to vector mosquitoes is critical for the implementation of effective control measures. A nulliparous susceptible Culex pipiens pallens (KSCP) laboratory colony and two field strains from Paju (PAJ) and Jeonju (JEO) Korea were evaluated for susceptibility to five pesticides by microapplication techniques. Unfed PAJ and JEO females demonstrated increased resistance compared to unfed KSCP females, respectively. While blood-fed KSCP females demonstrated <10-fold decreased susceptibility to pesticides compared to unfed KSCP females, blood-fed PAJ and JEO females demonstrated 25.0–50.0- and 16.0–38.6-fold increased resistance compared to unfed PAJ and JEO females, respectively. Unfed and blood-fed groups were assayed for α- and β-esterase, glutathione S-transferases, and cytochrome P-450 (P450) enzyme activity assays. P450 activity was 58.8- and 72.8-fold higher for unfed PAJ and JEO females, respectively, than unfed KSCP females. P450 enzyme activity of KSCP females assayed 1 and 7 days after a blood meal increased by 14.5- and 11.8-fold, respectively, compared to unfed KSCP females, while PAJ and JEO females demonstrated 164.9- and 148.5- and 170.7- and 160.4-fold increased activity, respectively, compared to unfed females of each population. However, other three resistance-related metabolic enzymes showed low activation at <10-fold after a blood meal. The data demonstrate that P450 acts on elevated insecticide resistance after blood meals in resistant field populations. Our findings might reveal that suppressing of the P450 protein by artificial gene mutation increases insecticidal susceptibility of Cx. pipiens and will promise effective vector mosquito control.

中文翻译：

---

在淡水库蚊的实验室和田间种群中，未喂食和喂血的杀虫剂抗药性和细胞色素P450活化。

了解杀虫剂对媒介蚊子的抗性机制对于实施有效的控制措施至关重要。通过微应用技术，评估了未生育的易感淡色库蚊（KSCP）实验室菌落以及来自坡州（PaJ）和全州（JEO）韩国的两个田间菌株对五种农药的敏感性。与未喂食的KSCP雌性相比，未喂食的PAJ和JEO雌性分别表现出更高的抵抗力。与未喂养的KSCP雌性相比，以血喂养的KSCP雌性对农药的敏感性降低了10倍，而与未喂养的PAJ和JEO雌性相比，以血液喂养的PAJ和JEO雌性的抵抗力分别提高了25.0-50.0-和16.0-38.6倍。 。对未进食和血液进食组的α-和β-酯酶，谷胱甘肽进行了测定小号-转移酶和细胞色素P-450（P450）酶活性测定。未喂养的PAJ和JEO雌性的P450活性分别比未喂养的KSCP雌性高58.8和72.8倍。与未进食的KSCP雌性相比，血餐后1天和7天测定的KSCP雌性的P450酶活性分别增加了14.5和11.8倍，而PAJ和JEO雌性的P450酶活性分别为164.9和148.5和170.7和160.4倍与每个人群的未进食雌性相比，活动分别增加。但是，其他三种与抵抗力有关的代谢酶在血餐后的<10倍处显示低活化。数据表明，在抗药性田间人群中，进餐后P450可提高杀虫剂抗药性。Cx。pipiens并有望实现有效的媒介蚊子控制。