Abstract
The systematic morphology of species within the Hyalomma (Euhyalomma) marginatum Koch complex of ticks is illustrated and their relationships within this assemblage are discussed. Traditionally this group comprises the extremely polymorphic species Hyalomma (Euhyalomma) marginatum Koch, 1844 subdivided into four subspecies, namely H. (E.) marginatum marginatum Koch, 1844; H (E.) marginatum rufipes Koch, 1844; H (E.) marginatum isaaci Sharif, 1928 and/H. (E.) marginatum turanicum Pomerantzev, 1946. A fifth member of the association, namely H (E.) glabrum Delpy, 1949, has recently been re-instated as a full species. The taxonomic rank of the first mentioned four ticks is herein raised to species level. Details on the repositories of type specimens, synonyms, descriptions, variability, hosts, geographic distribution, and disease relationships of these four ticks are provided, and all their developmental stages are illustrated.