A revision of the Mauna Walker, 1865 and Illa Warren, 1914 group of genera (Lepidoptera: Geometridae: Ennominae: Nacophorini)

The present revision is the final instalment in a series of contributions aimed at revising a species-rich assemblage of afrotropical ennomine geometrids putatively placed in the predominantly southern hemisphere tribe Nacophorini. All accessible primary types were examined. Mauna Walker in the previously accepted sense proved to be polyphyletic, and all its constituent taxa except for the type species M. filia (Cramer) had to be transferred to other genera, several of them described as new below. The previously monotypic genus Illa Warren in its revised sense has four members: the type species I. nefanda Warren, 1914, I. perquisita (Prout, 1922) comb. nov. and I. reprobata (Prout, 1938) comb.nov., stat. nov., both transferred from Mauna; the latter taxon is also raised to specific status, with one species (Illa altipaludis spec. nov.) being described as new. Five genera are erected as new. The most species-rich of these is Terpnostola gen. nov., with a total of 23 species placed in seven informally named species groups plus one species of uncertain position within the genus being described as new: Terpnostola intermedia spec. nov., T. crocopeplus spec. nov., T. punctilinea spec. nov.; T. mediolineata spec. nov.; T. perlineata spec. nov.; T. strigulata spec. nov., T. gratiosata spec. nov. and T. nyassica spec. nov. (intermedia group); T. exalbescens spec. nov. and T. nguruensis spec. nov. (exalbescens group); T. pelostolmus spec. nov.; T. igneotincta spec. nov., T. insignitata spec. nov. and T. silvaeiuniperi spec. nov. (pelostolmus group); T. crenata spec. nov. (crenata group); T. tardenota spec. nov. (electa group); T. instabilis spec. nov., T. inspersa spec. nov., T. chitipensis spec. nov., T. kasungensis spec. nov., T. propinqua spec. nov. and T. philocydes spec. nov. (sematurga group). Terpnostola valdepurpurea spec. nov. is known only from the female holotype and could not be assigned to any of the above groups; it is therefore treated as being incertae sedis within the genus. Six new combinations, all from Mauna, are proposed within Terpnostola: T. ardescens (Prout, 1916) comb. nov., T. rwandana (Herbulot, 2001) comb. nov., T. diasporas (Prout, 1932) comb. nov., T. electa (Prout, 1917) comb. nov., T. sematurga (Prout, 1938) comb. nov., and T. zomba (Herbulot, 1997) comb. nov. A further four monotypic new genera are erected as their constituent species do not share the synapomorphies characterizing Terpnostola gen. nov. or any previously described genera: Asemoprepes gen. nov., to accommodate Gonodontis homales Prout, 1922 (comb. nov.); Eutelostolmus gen. nov., to accommodate Mauna pictifimbria Prout, 1938 (comb. nov.); Eucopelates gen. nov. is solely composed of the type species E. perstrigulatus spec. nov., and Dispatha gen. nov. presently only contains the type species D. pelopasta spec. nov. In the absence of male specimens the correct generic placement of Pareclipsis anophthalma Prout, 1916 could not be established, although adult habitus suggests that this taxon is not referable to Pareclipsis Warren, 1894 but should probably be placed in the Mauna/Illa group of genera. Keys to the genera, as well as to species groups and species within Terpnostola are provided, as are illustrations of adults and genitalia and distribution maps to the southern African species. The revision is complemented by a gazetteer.