Optimize ratios of clove and cinnamon essential oil incombination with ethanol and water in controlling house dust mite (Dermatophagoides pteronyssinus (Trouessart)) by fumigation method
Abstract:
Acaricidal property of essential oils from clove, cinnamon and eugenol diluted in ethanol and water in different ratios and concentrations against house dust mite, Dermatophagoides pteronyssinus in laboratory was performed by fumigation method. The mentioned formulas at the volume 1.5 ml were applied within 25 L Knockdown chamber found that clove essential oils diluted in ethanol and water (95:5) could kill house dust mite 100% at concentration of 0.6 µl/L air which was not different from eugenol. Followed by cinnamon essential oil that could kill house dust mite 90.4% Different ratios between clove and cinnamon essential oils diluted in ethanol and water at different proportions were prepared and tested to the house dust mite in laboratory. The results show that clove mixed with cinnamon essential oils at ratios 2:1 (incombination with ethanol and water at 95:5 ratio) gave better efficiency in killing dust mite than than that of ratios 1:1 and 1:2 at1.2 µl/L air. At the same time, clove and cinnamon essential oils with 2:1 ratio and ethanol: water and 80:20 ratio was effective at killing dust mites 81.1%with LC₅₀ equal to 0.63%. Those essential oils were then tested to the mite kept in the simulation bedroom when clove mixed with cinnamon at the ratio of 2:1 diluted in ethanol and water at the ratios of 95:5 and 70:30 at the concentration of 2 and 3% were applied in 1×1×1 m3glasschamber where the small mattress size 1×1 m was put and amount of 10 mites kept in mite cage was inserted to the mattress. The fumigation was made for 2 hours. The experiment was done with 3 replications. The result showed that clove mixed with cinnamon essential oil dulutted in ethanol 95% (5% water)at the concentration at 2 and 3% presented 94.3 and 98.9%, respectively. It was better than that of it diluted in ethanol 70% (30% water), which gave 81.7 and 87.1%mortality, respectively. As for the experiment of field study when those 2 formulations were applied to the mattress in the bedroom with amount of 25 ml/m². Number of mite was observed at2 hr. after application as well as at 7 and 14 days. The result informed that the essential oils diluted in ethanol 95% (5% water) at the concentration of 3% showed the best control of mite. However, new emergent mite of 0.6 mite/ 1 g dust were found after 14 days application.