白纹伊蚊和淡色库蚊冷冻麻醉法初探

A preliminary study of cryoanesthesia of Aedes albopictus and Culex pipiens pallens

目的用冷冻法麻醉白纹伊蚊和淡色库蚊,探究最佳冷冻麻醉的时间及冷冻后蚊虫的生存状况,为蚊虫生物测定前的麻醉提供科学依据。方法各取一定数量的白纹伊蚊和淡色库蚊蚊蛹装入不同的蚊笼中,获得羽化的白纹伊蚊和淡色库蚊成蚊各4笼,待其羽化2～3 d后分别将其放入(-20±0.5)℃的冰柜中5、10、15和30 s,取出并观察蚊虫的击倒率和首只复苏时间,再将其连同各自的对照组一起放入饲养室进行常规饲养,观察并记录蚊虫日生存情况,比较不同冷冻组蚊虫冷冻后的中位生存时间和生存曲线差异。结果白纹伊蚊经过5、10、15和30 s冷冻后击倒率均为100%,其中冷冻5 s组与对照组冷冻后生存曲线差异无统计学意义(χ~2=1.441,P=0.230),而冷冻10和15 s组冷冻后生存时间均显著低于对照组(χ~2=24.407、38.375,P<0.01),冷冻30 s组冷冻后均未复苏。取5笼白纹伊蚊将其冷冻5 s后分别放置于冰排3、5、10、30和60 min,观察首只复苏时间和日生存情况,发现放置于冰排3 min的白纹伊蚊首只复苏时间为145 s,其冷冻后雌蚊与对照组雌蚊比较生存曲线差异无统计学意义(χ~2=2.463,P=0.117),而放置于冰排5、10、30和60 min的冷冻后雌蚊生存曲线均显著低于对照组(χ~2=15.141、22.518、30.242、43.672,P<0.01)。淡色库蚊经过5、10、15和30 s冷冻后击倒率分别为64.00%、85.19%、100%和100%,冷冻15 s组的首只复苏时间为3 s,冷冻30 s组的首只复苏时间为138 s。各实验组与对照组成蚊冷冻后生存曲线差异无统计学意义(χ~2=7.225,P=0.124)。结论用冷冻法麻醉白纹伊蚊的最佳时间组合为冷冻5 s然后放置于冰排3 min,而麻醉淡色库蚊的最佳时间是冷冻30 s。

Objective To investigate the optimal cryoanesthesia time for Aedes albopictus and Culex pipiens pallens and the survival status of them after cryoanesthesia, and to provide a scientific basis for anesthesia before mosquito bioassay.Methods A certain number of pupae of Ae. albopictus and Cx. pipiens pallens were put into different mosquito cages to obtain four cages each of emerged Ae. albopictus and Cx. pipiens pallens. At 2-3 days after emergence, they were stored in a freezer(-20±0.5) ℃ for 5, 10, 15, and 30 s, respectively. They were taken out to observe the knock-down rate and first recovery time. And then they were given routine feeding in feeding rooms together with their respective control groups.Their survival status was observed and recorded. The median survival time and survival curve were compared between different freezing groups. Results The knock-down rates of Ae. albopictus after 5, 10, 15, and 30 s of freezing were all100%. There was no significant difference in survival curve between the 5 s group and its control group( χ~2=1.441, P=0.230), while the 10 s group and 15 s group had significantly shorter survival time compared with their respective control groups( χ~2=24.407, P<0.01;χ~2=38.375, P<0.01). There were no recovering mosquitoes in the 30 s group. Five cages of Ae. albopictus from the 5 s group were put on ice floe for 3, 5, 10, 30, and 60 min, respectively. The first recovery time and daily survival status were observed. The first recovery time of Ae. albopictus in the 3 min group was 145 s, and there was no significant difference in survival curve between the female mosquitoes in this group and those in its control group( χ~2=2.463, P=0.117);however, the female mosquitoes in the 5, 10, 30, and 60 min groups had significantly lower survival curves compared with their respective control groups( χ~2=15.141, P<0.01;χ~2=22.518, P<0.01;χ~2=30.242, P<0.01;χ~2=43.672, P<0.01). The knock-down rates of Cx. pipiens pallens after 5, 10, 15, and 30 s of cryoanesthesia were 64.00%,85.19%, 100%, and 100%, respectively. The first recovery times for the 15 s group and 30 s group were 3 s and 138 s,respectively. There was no significant difference in survival curve between the test groups and their control groups( χ~2=7.225, P=0.124). Conclusion For Ae. albopictus, the optimal operation procedure for cryoanesthesia is 5 s freezing and 3 min placement on ice floe, while the optimal time for Cx. pipiens pallens is 30 s freezing.