Structure of Haller’s Organ and Taxonomy of Hard Ticks of the Subfamily Amblyomminae (Family Ixodidae)

The structure of Haller’s organ, the main sensory organ of hard ticks, studied by methods of scanning electron microscopy, was analyzed on the basis of my own and literary data in 40 species of the subfamily Amblyomminae (Metastriata), representatives of the genera Amblyomma Koch, 1844 (10 species, including 3 species earlier separated as the genus Aponomma), Anomalohimalaya Filippova, 1994 (1 species), Dermacentor Koch, 1844 (6 species), Haemaphysalis Koch, 1844 (6 species), Hyalomma Koch, 1844 (6 species), Margaropus Pomerantzev, 1947 (1 species), and Rhipicephalus Koch, 1844 (10 species, including 2 species earlier separated as the genus Boophilus). The main taxonomic characters were distinguished, including the number and topography of sensilla in the anterior pit and the shape of the capsular orifice. It was shown that the structure of Haller’s organ is specific of separate genera, whereas differences between species and subgenera are insignificant. On the basis of these results, latest revisions of the Metastriata, based exclusively on molecular and genetic data seem doubtful. Comparison of the obtained data with the existing views on the taxonomy of the subfamily Amblyomminae is performed.