A new species, Allocaeculus sirwani sp. nov. (Trombidiformes: Prostigmata: Caeculidae) is described based onadult females from Marivan city, Kurdistan Province, Iran. The new species can be distinguished from other species by the following features: the bothridial setae (bo) filiform; dorsal body setae clavate; setae c1, a2, d1, d2, e1, e2 present; setae c1 normal; adanal and pseudanal plates each bearing three pairs of setae; un-pair seta hspresent; palp tarsus with seven setae; epimeral setal formula 3-2-2-4/5 and spinose setal formula of leg I 3-2-1-1-2. Also, an identification key to known species of Allocaeculus is provided.
