百合科寄主植物对韭菜迟眼蕈蚊的生物效应

室内分别用百合科韭菜、大葱、大蒜和圆葱饲喂韭菜迟眼蕈蚊Bradysia odoriphaga Yang et Zhang幼虫，研究了4种寄主植物对其生长发育和繁殖的影响；用气-质谱联用分析技术，检测了人工合成大蒜素及大蒜、圆葱和韭菜的乙醇提取物的主要化学成分。结果表明，4种供试寄主植物对韭菜迟眼蕈蚊生长发育和繁殖的影响存在差异，幼虫取食韭菜最有利于其生长发育和繁殖；取食大蒜和圆葱对其生长发育和繁殖表现出明显的不利性，主要表现为幼虫死亡率增加，幼虫期延长，蛹重减轻，单雌产卵量降低；而取食大葱的影响介于取食韭菜与取食大蒜和圆葱之间。大蒜、圆葱的乙醇提取物和人工合成的大蒜素均对韭菜迟眼蕈蚊1龄幼虫有不同程度的杀虫活性，大蒜和圆葱的乙醇提取物（干粉，2 g/mL）稀释100和200倍，处理后48 h对1龄幼虫的校正死亡率分别达54.7%、28.0%和49.4%、22.7%；10%大蒜素稀释500和1 000倍，处理后48 h校正死亡率达100%和80.0%。成分分析表明硫醚类化合物可能是大蒜和圆葱中含有的杀虫活性物质之一。

Biological effect of liliaceous host plants on Bradysia odoriphaga Yang et Zhang (Diptera: Sciaridae)

The effect of the different liliaceous host plants on the growth, development and reproduction of Bradysia odoriphaga Yang et Zhang was studied by feeding its larvae with four host plants, Allium tuberosum, A. fistulosum, A. sativum and A. cepa respectively in the laboratory. The main chemical constituents of garlicin and alcohol extracts from A. sativum, A. cepa and A. tubersoum were analyzed using gas chromatography and mass spectrometry. The results demonstrated that the effect of four host plants on the growth, development and reproduction of Bradysia odoriphaga was different. The most favorable food in the four host plants for the growth, development and reproduction of the pest was A. tubersoum. When the larvae were fed with A. sativum and A. cepa, the death rate of the larvae increased, the larval stage prolonged, the pupal weight decreased, and the average fecundity reduced. The insecticidal activities of the alcohol extracts from A. sativum and A. cepa, and the synthetic garlicin against its first instar larvae were different. When the first instar larvae were treated with the alcohol extract (2 g dry powder/mL) from A. sativum and A. cepa, which was diluted 100 and 200 times, their corrected mortality after 48 hours was 54.7% and 28.0%, and 49.4% and 22.7%, respectively. However, when the first instar larvae were treated with 10% garlicin, which was diluted 500 and 1 000 times, their corrected mortality after 48 hours was 100% and 80.0%, respectively. Chemical constituent analysis showed that thioether compound might be one of insecticidal substances in A. sativum and A. cepa.