Sustained efficacy of the novel topical repellent TT‐4302 against mosquitoes and ticks

Mosquitoes and ticks are blood‐feeding pests of humans and animals that can vector many important aetiological agents of disease. Previous research demonstrated that TT‐4302 (Guardian^® Wilderness) containing 5% geraniol applied to human subjects gave 5–6 h of repellency against mosquitoes (depending on species) and was repellent to ticks in vitro. This study was conducted to obtain an independent third‐party evaluation of TT‐4302 against Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) mosquitoes and to test the efficacy of the product in the field against ticks. TT‐4302 provided an average of 6.5 h of repellency of ≥ 95% Weibull mean protection time: 7.4 h, 95% confidence interval (CI) 5.8–11.3 h] for St. aegypti, whereas a 15% DEET formulation provided 4.7 h of repellency (Weibull mean protection time: 5.2 h, 95% CI 3.7–6.9 h). In tick field trials, the efficacy of TT‐4302 did not differ significantly from that of a 25% DEET formulation against Amblyomma americanum (Ixodida: Ixodidae). TT‐4302 was 81.3% repellent at 2.5 h after application, whereas DEET was 77.2% repellent at the same time‐point. Results at 3.5 h after application were 71.4% for TT‐4302 and 72.9% for DEET.