Orientational behavior of the ixodid tick Hyalomma asiaticum under desert conditions

The orientational behaviour of the imago of ticks in natural conditions is based on the optimal using of relatively primitive eyes with the development of a specific mechanism of orientation. A statistical study of tracks of ticks together with the analysis of the optical system and functional possibilities of the eyes have made it possible for the author to suggest a model of orientational mechanism based on different signal meanings of increasing and decreasing of light intensity registered by the eyes from the direction of their main optical axes.