Leptus (Leptus) delijanensis Khademi, Saboori & Hakimitabar sp. n. (Acari: Erythraeidae) is described and illustrated from larva ectoparasitic on undetermined grasshopper (Orthoptera: Acrididae) from Delijan, Markazi Province, Iran. It is the first report of Leptus species with solenidion of TFe I from Asia. A key to larval species of Leptus with solenidion on TFe I of the world is presented.