XV International Congress of Acarology (XV ICA), 2 - 08 September 2018, pp.195
Distinguishing characters of the species in the genus Cheylostigmaeus Willmann (Acari:
Stigmaeidae) such as the structure of the gnathosoma are mainly based on males. In this genus, the gnathosoma may show sexual dimorphism unlike other members of the family. Polymorphism may occur in males of this genus. The homeomorphic males resemble the females in the absence of lamellae on subcapitulum. The lamellae and/or the palpal apophyses are characteristic of heteromorphic males. In the present work, morphological variations in distinguishing characters in five topotypic male specimens were identified in C. variatus Doğan, Dilkaraoğlu & Fan. The variations in the shapes of lamellar projections, verrucae on the dorsal surfaces of chelicerae and structures of apophyses on palpal segments in these specimens were noted. We consider that the
differences in the specimens were intraspecific variations and that there was not enough evidence to justify a new species. This hypothesis may be supported by the rearing of a population of C. variatus or molecular evidence.