The morphology of the larval stages of Arrenurus biscissus, A. pugionifer and A. bisulcicodulus is described. The three species belong to the subgenus Micruracarus and share several characters. The larvae of the three species differ in the shape of the dorsal plate, shape of the excretory pore plate, ratio between length of coxal plate median margins, and the numbers of pectinating setae on fifth palpal segment (PV). The larva of A. biscissus is very similar to the closely related A. sinuator. Larvae of A. pugionifer and A. bisulcicodulus resemble other Micruracarus species (A. bifidicodulus, A. inexploratus, A. integrator).