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在室内条件下测试了土荆芥Chenopodium ambrosioides叶片的石油醚提取物及精油对冈比亚按蚊Anopheles gambiae0～2d龄成虫和1～4龄幼虫的毒性。每一龄期各取30头幼虫分别接触50,100,250,500,750和1000mg/L提取物和精油,于24h和48h后记录死亡幼虫的数目。30头成虫在密封的长方形玻璃笼子中分别接触0.8,1.6,2.4μL/L土荆芥精油蒸气,24h后记录死亡率。结果表明,测试的提取物和精油对冈比亚按蚊的各龄幼虫和成虫均具有毒性。48h致死中浓度(LC50)的测试结果表明,石油醚提取物对1龄幼虫的毒性最强(14.89mg/L),其次是对4龄幼虫(18.90mg/L),对3龄幼虫的毒性最低(183.77mg/L);精油对4龄幼虫毒性最强(36.62mg/L),其次是对1龄幼虫(90.75mg/L)。推算的土荆芥精油对冈比亚按蚊的LC50为1.01μL/L。本研究揭示了土荆芥对冈比亚按蚊的防治潜力。
The petroleum ether extract and essential oil of Chenopodium ambrosioides were tested for their toxicity to adults 0 to 2 d of Anopheles gambiae and 1 to 4 instar larvae of Anopheles gambiae. Thirty larvae of each age were exposed to 50, 100, 250, 500, 750 and 1000 mg / L of extract and essential oil, respectively, and the number of dead larvae was recorded after 24 and 48 hours. Thirty adult adults were exposed to 0.8, 1.6 and 2.4 μL / L Nepean essential oil vapors in a sealed rectangular glass cage, respectively, and the mortality was recorded after 24 h. The results showed that the tested extracts and essential oils were toxic to all larvae and adults of Anopheles gambiae. The LC50 of 48h showed that the petroleum ether extract was the most toxic to the first instar larvae (14.89mg / L), followed by the fourth instar larvae (18.90mg / L) and the toxicity to the 3rd instar larvae The lowest was (183.77 mg / L). The essential oil had the highest toxicity (36.62 mg / L) to the 4th instar larvae, followed by the first instar larvae (90.75 mg / L). The estimated LC50 of soil of Schizonepeta tenuis against Anopheles gambiae is 1.01 μL / L. This study revealed the potential for control of Anopheles gambiae by Nepeta mosquitoes.