Figure 4
From: Mosquito repellence induced by tarsal contact with hydrophobic liquids
Wetting-liquid-based repellent is effective on human and hippopotamus skin. (a). Diagram of mosquito biting assay. Exposure area of forearms is 4 cm × 5 cm. (b) Mosquito bites on liquid-coated forearms. L-PDMS (orange circle) and H-PDMS (dark green circle). Application ratio: 0.25 mg/cm2. Horizontal line represents the mean ± s.e.m. (n = 5). Different letters (A or B) indicate significant variance between liquids (one-way ANOVA with the Tukey post hoc test, P = 10–13). (c) Hippopotamus amphibius male born in 1982 and red sweat. (d) Force value with respect to the immersion depth of mosquito forelegs. The value is obtained with the experimental setup used in Fig. 1e (n = 6–7). Hippo secretion (dark red circles), water (purple circles). The experiment with the hippo secretion was conducted by pouring ~ 0.5 mL into a small plastic petri dish. (e) Contact-time of mosquitoes on ground glass substrates coated with liquids (n = 10–14). Application ratio of hippo secretion and water: 2.0 mg/cm2. Applying liquids did not affect the attraction behaviour of mosquitoes to the landing area (glass substrates) (Supplementary Fig. S4c). Application ratio of silica nanoparticle suspension in L-PDMS: 0.25 mg/cm2. Hippopotamus secretion: γ = 25.1 mN/m. Suspension: γ = 18.9 mN/m. The letters (A or B) indicate the significant variance between the different liquids (one-way ANOVA with the Tukey post hoc test, P = 4.37 × 10−4). The contact time of each trial is displayed in Supplementary Table S3.
