Abstract: Spatial repellents are now becoming important part of integrated vector management and are considered another vector-borne disease prevention tool as well as disease transmission breaking strategy. However, spatial repellents against ticks are still out of focus, in spite of the fact that humans are at a high risk of tick-borne diseases. Evaluations of spatial repellents are an important part of their development process and are key to determine the worthiness of the repellents. These evaluations against ticks are carried out either to assess efficacy of AI, the effectiveness of delivery system or a combination of both. These evaluations could be in the laboratory, under semi-field or under field conditions. Many such techniques are discussed in this presentation. D-allethrin vapors generated by a personal mosquito repellent device were evaluated for its efficacy to spatially repel lone star ticks in a wind tunnel and in an olfactometer. Only adults were evaluated in the wind tunnel whereas adults and nymphs were evaluated in the olfactometer. The results of the wind tunnel study indicated some reduction in movement of ticks to the attractant, i.e., 31 % compared to 49% in control. In the olfactometer tests, 87% adults moved away from repellent compared to 27 % in control. These numbers were 43 and 20 % for nymphs.
