土荆芥的石油醚提取物及精油对冈比亚按蚊的杀虫活性(英文)

Insecticidal activity of petroleum ether extract and essential oil of Chenopodium ambrosioides L.(Chenopodiaceae) against Anopheles gambiae(Diptera:Culicidae)

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。

Tests were carried out to evaluate the toxicity of Chenopodium ambrosioides （Chenopodiacea） leaf against the 0 -2 d old adult, 1st, 2nd, 3rd and 4th instar larvae of Anopheles gambiae （Diptera： Culicidae） as petroleum ether extract and essential oil respectively at ambient laboratory temperature. Thirty larvae at each instar stage were exposed to 50, 100, 250, 500, 750 and 1 000 mg/L of extract and essential oil in water, and the number of dead larvae recorded at 24 and 48 h post-exposure. Thirty adults were exposed to C. ambrosioides oil vapour in air-tight rectangular glass cages at 0.8, 1.6 and 2.4 μL/L and mortality recorded 24 h after exposure. The results showed that the test extract and essential oil were toxic to all larval stages and adults of An. gambiae. The median lethal concentration after 48 h exposure （48 h-LC50 ） values show that the extract was most toxic to the 1st instar larvae （14.89 mg/L） followed by the 4th instar （18.90 mg/L） and least toxic to the 3rd instar （183. 77 mg/L）. The 48 h LCs0 values showed that the essential oil was most toxic to the 4th （36.62 mg/L） followed by the 1st instar （90.75 mg/L） larvae. The computed LC50value of C. ambrosioides oil against adult An. gambiae was 1.01μL/L. The study highlights the potential of C. ambrosioides for the control An. gambiae.