飞机草提取物对红脉穗螟的产卵忌避及杀卵活性

为探讨飞机草提取物对红脉穗螟Tirathaba rufivena Walker的防控潜力,采用室内生物测定法,研究了飞机草提取物对红脉穗螟的产卵忌避作用和杀卵活性。结果表明,飞机草乙酸乙酯提取物对红脉穗螟的忌避效果最好,选择性和非选择性忌避率分别为41.85%和46.84%;不同提取物处理红脉穗螟的卵后,均造成卵孵化率降低和初孵幼虫的死亡,其中乙酸乙酯提取物对红脉穗螟卵的影响最大,孵化率和1龄幼虫死亡率分别达到65.89%和40.37%。对飞机草乙酸乙酯提取物进行分级萃取测试各萃取物的活性发现,正己烷萃取物对红脉穗螟的产卵忌避作用和杀卵活性最强。田间试验表明,采用正己烷萃取物稀释50倍和100倍浓度进行田间喷雾,药后15 d对红脉穗螟的种群控制率可达到50%以上。

Oviposition deterrence and ovicidal activity of Eupatorium odoratum extracts of Tirathaba rufivena Walker

In order to explore the control potential of Eupatorium odoratum extracts on Tirathaba rufivena Walker, the oviposition deterrence and ovicidal activity of E odoratum extracts against T. Rufivena were studied with bioassay methods in the laboratory. The results indicated that the extracts of ethyl acetate showed the best oviposition deterrent activity among different solvents extracts, the deterrent rate of choice and non-choice test were 41.85% and 46.84%, respectively. All of the different solvent extracts of E odoratum could cause the egg hatchability reduced and hatching larvae with different degrees of death, and ethyl acetate extracts showed the highest activity to the egg, the corrected egg hatchability rate and mortality of 1st instar larvae were 65.89% and 40.37%, respectively. Among the different solvent extracts of E. Odoratum ethyl acetate extraction, the hexane extracts showed the best activities on oviposition deterrent and ovicidal activity. Field experiments showed that after sprayed with the diluted concentration of the hexane extract of ethyl acetate extraction at 50 and 100 times, the population control effects of T. Rufivena could reach more than 50% after teated 15 days.