The Fumigation Activity of Essential Oil from Vernonia esculenta Against Red Imported Fire Ant

In this study, the chemical composition analysis of essential oil of Vernonia esculenta(VE) and its effect on the control of red imported fire ant(RFIA) were studyed. The essential oil of VE was extracted by water distillation and the compounds were analysed by GC−MS, then the fumigation activity of VE against red imported fire ant was tested. The result showed that the yellow and transparent essential oil with strong aroma was extracted from VE by water distillation, and the extraction rate of VE reach about 1.23%. And 15 compounds were identified, the major constituents of VE are α−Amyrin and β−Amyrin with 23.00% and 36.98%, respectively. The insecticidal activity of the essential oil against RFIA increased with treatment time and concentration increasing , and the highest mortality rate was 100% after 4 h and 6 h treatment at the concentrations of 200 μL/L and 100 μL/L , respectively. The alive RFIAs were selected and cultured normally after teratment LT₅ and LT₁₀ at 200 μL/L concentration, while all RFIAs died during 6 h and 5 h respectively. The essential oil of VE has high fumigation activity against red imported fire ants, and the damage is irreversible. This study can provide a new way against RFIA.