Before each test, the readiness of the mosquitoes to bite was confirmed by having subjects insert their untreated forearm into the test cage. Once subjects observed five mosquito landings on the untreated arm, they removed their arm from the cage and ap- plied the repellent being tested from the elbow to the fingertips, following the instructions on the product’s label. After the appli- cation of the repellent, subjects were instructed not to rub, touch, or wet the treated arm. Repellent-impregnated wristbands were worn on the wrist of the arm being inserted into the cage. Sub- jects were provided with a standardized log sheet to ensure accu- rate documentation of the duration of exposure and the time of the first bite. The elapsed time to the first bite was then calculated and recorded as the “complete-protection time” for that subject in that particular test.
Subjects were asked to follow the testing protocol shown in Figure 1. Subjects conducted their first test of each repellent by inserting the treated arm into a test cage for one full minute every five minutes. If they were not bitten within 20 minutes, then the
The IR3535-based repellent protected against mos- quito bites for an average of 22.9 minutes. The cit- ronella-based repellents we tested protected for 20 minutes or less. There was no significant difference in protection time between the slow-release formulation containing 12 percent citronella and the formulation