New species of the genus Stephens from Africa (Trichoptera, Philopotamidae) and characterization of the African groups and subgroups of the genus.

This paper is primarily based on collections in Tanzania and Ghana in 1990-1991 and 1991-1994, respectively. In all, 46 species of were collected, 31 of them new species. All these species are illustrated or re-illustrated and described in the paper. Additionally, five species from Africa from collections in Illinois and Minnesota, four of them new, are included. This provided the incentive to review the species of from the African subregion and assign the majority of them to species groups and subgroups. In the process, several species were synonymized. In all 147 valid species are recognized, of which 51 are treated in this paper. Two major species groups are recognized for Africa, the Group and the Group. The former is based on the type species for the genus; this is the first formal characterization of this group, as distinct from other species groups in the subgenus. Mainland African species in the Group mostly fall into four large species-diverse subgroups, but a number of smaller subgroups are also recognized. Membership in these subgroups is specified for the majority of African species and characters defining the subgroups informally discussed. The Group includes a single Asian species and nine previously described African species. They are assigned to two subgroups, one newly recognized in this paper. Several additional species were considered unassigned to subgroup within the Group. The majority of the new species described in this paper belong to the Group.