Repellent activity screening of 12 essential oils against Aedes albopictus Skuse: Repellent liquid preparation of Mentha arvensis and Litsea cubeba oils and bioassay on hand skins

The repellent activities of 12 selected essential oils against Aedes albopictus were evaluated using a Y-tube olfactometer. Mentha arvensis oil showed the best repellent activity among the selected oils, with 91.66% percentage repellency at 20 min, followed by Litsea cubeba oil (73.94%) and Laurus nobilis oil (67.12%). The repellent activities of nine designed and prepared repellent liquid formulas were tested against Ae. albopictus using the arm-in-cage method. The optimal formula of the repellent liquid was defined as "10% Litsea cubeba oil + 10% Menthe arvensis oil + 5% Tween 80 + 5% vanillin + 70% absolute ethyl alcohol." The effective hand skin protection time of this liquid formula is 4 h, indicating its potential product development value. L. cubeba and M. arvensis oils can be used as green repellents for mosquito control because of their low toxicity and environmental friendliness.