Chelicerae of most Parasitiform mites have retained the same general set of plesiomorphic structures and functions. For mesostigmatid mites this represents grabbing, cutting, piercing and, in the males of some groups, transferring sperm (Di Palma 2009).
Di Palma, A., Wegener, A. & Alberti, G. (2009) On the ultrastructure and functional morphology of the male chelicerae (gonopods) in Parasitina and Dermanyssina mites (Acari: Gamasida). Arthropod Structure & Development, 38 (4), 329–338. https://doi.org/10.1016/j.asd.2009.01.003