Three types of sensilla were distinguished during scanning electron microscope investigations of the palpal sensory organ, one of the main organs in food suitability detection, in 8 species of mites belonging to the genera Gamasellus, Macrocheles, Euryparasitus, Eulaelaps, Myonyssus, Raillietia, Spinturnix, and Pneumonyssus. Two types (A and B) are chemo-mechanoreceptor single-walled and double-walled sensilla (SW-UP and DW-UP) and one type (M) is represented by mechanoreceptor (NP) sensilla. It is shown, that no type of feeding influences the structure of palpal organ, whereas a character of host-parasite relationship (transition to constant parasitism and parasitism in cavities of inner organs) leads to oligomerization and reduction of chemoreceptor sensilla.