DOSE-PERSISTENCE RELATIONSHIP OF THREE TOPICAL REPELLENT COMPOUNDS AGAINST AEDES ALBOPICTUS AND CULEX NIGRIPALPUS

The experimental piperidine compounds 1-(3-cyclohexen-1-ylcarbonyl)-2-methylpiperidine (AI3-37220), 1-(3-cyclohexen-1-ylcarbonyl) piperidine (AI3-35765), and N, N-diethyl -3- methylbenzamide (DEET) were evaluated for the persistence of repellency against laboratory-reared Aedes albopictus Skuse and Culex nigripalpus Theobald using a modified dose-persistence test procedure on human volunteers. The protection time (hours) provided by the tested repellent compounds against the two species of mosquitoes were proportional to the dose applied. Overall, higher application rates of each repellent compound were found to provide longer mean duration of protection from bites (MDPB) of the two species of mosquitoes. The repellent DEET tested against each mosquito species provided better protection time than the experimental repellent compounds AI3-37220 and AI3-35765. The three repellent compounds at 20 and 25% application rates provided the MDPB of Ae. albopictus for 5-8 hours and at 5, 10 and 15% provided the MDPB of Cx. nigripalpus for 5-7 hours. The MDPB provided by the three repellent compounds against Cx. nigripalpus was longer than that against Ae. albopictus. Also, the MDPB provided by each tested repellent compound varied from the individual human volunteer.