Humidity effects on response ofArgas persicus (Oken) to guanine, an assembly pheromone of ticks

The assembly behavior of the tickArgas persicus Oken in response to guanine has been found to be humidity dependent. Nymphal and adult maleA. persicus assemble on guanine-treated paper disks only at low relative humidities (25 ± 5%). Exposure of the ticks to high relative humidities (85 ± 5%) results in a gradual induction of a negative response to the pheromone.