Five species of Corethromyces parasitize staphylinid beetles (Coleoptera) of the genus Scopaeus: C. fuscipes, C. minusculus, C. scopaei, C. scopaeicola and C. striatus; the latter is here described as new. Except for C. fuscipes, the remaining species were studied on the basis of observations on type specimens. Corethromyces striatus is distinguished from the other related species by the striation of the preapical zone of the perithecium and by the primary appendage, which consists of a distinctive main axis bearing secondary branches on one or both sides. Full descriptions, photographs and other observations for these taxa are furnished. A dichotomous key to separate the species is also provided.