Insecticidal activity of essential oil derived from horseweed Conyza canadensis (L.) Cronq. against two mosquitoes and its volatile components

【Aim】To study the insecticidal potential and active ingredients of essential oil from horseweed Conyza canadensis (L.) Cronq. 【Methods】The insecticidal activity of the essential oil against Aedes albopictus and Culex pipiens quinquefasciatus was assayed with immersion method and fumigation method. The volatile components of this oil were also qualitatively analyzed by gas chromatography-mass spectrometry. 【Results】The LC50values of the essential oil from C. canadensis against the 1st- 4th instar larvae and pupae of Ae. albopictus at 24 h after treatment were 25. 01,45. 88,56. 94,64. 60 and 346. 23 μg / mL,respectively,while those against the 1st- 4th instar larvae and pupae of Cx. pipiens quinquefasciatus were 9. 16,8. 65,32. 12,43. 68 and 197. 83 μg / mL,respectively. At the dosages of 48,64,80,96,112 and 128 μg / cm3,the KT50values of the essential oil from C. canadensis against adults of Ae. albopictus and Cx. pipiens quinquefasciatus were 28. 81,22. 31,20. 38,17. 05,13. 92 and 9. 74 min,and 34. 90,32. 97,23. 97,19. 60,15. 20 and 10. 34 min,respectively. The LC50values of the essential oil against adults of Ae. albopictus and Cx. pipiens quinquefasciatus at 24 h after fumigation were 75. 46 and 99. 19 μg / cm3,respectively. Thirty-one compounds were separated and identified from volatiles of C. canadensis essential oil,including 6 monoterpenes,17 sesquiterpenes and 6 oxygenated sesquiterpenes. 【Conclusion】These results demonstrate that the insecticidal activity of C. canadensis essential oil against the two mosquito species is remarkable and the oil has a potential for further development.

Hali tarjima qilinmagan