Parasepedon, sensu Verbeke, 1950

Knutson, Lloyd V., Deeming, John C. & Ebejer, Martin J., 2018, The Snail-killing Flies (Diptera: Sciomyzidae) of West Africa, Zootaxa 4483 (1), pp. 67-100 : 78-79

Subgenus Parasepedon

Comments on species groups in Parasepedon

The many species-groups of Parasepedon proposed by Verbeke (1950, 1961) have not been rigourously discussed. With the large number of species in Parasepedon it is logical that there have been attempts to place them in groups. Furthermore, placing species in groups may be useful as indications of relationships that could be useful in working out the life cycles of many biologically unknown species of Parasepedon . Steyskal in Steyskal & Verbeke (1956) stated (p. 3) “Verbeke has arranged the species [of Parasepedon ] in seven groups designated by letters of the alphabet [but also with an included species name], but a few species do not fit well in any group, and it seems preferable not to make use of group designations.…” Verbeke’s (1950) seven groups of Parasepedon including most but not all known species were “ A Groupe ornatifrons —4 species; B Groupe notambe —3 species; C Groupe convergens —3 species; D Groupe senegalensis —4 species; E Groupe ochripes —2 species; F Groupe paranana —3 species; G Groupe trichrooscelis —6 species. However, Verbeke (1961, 1962b, 1963) continued to use species-groups. Verbeke (1961) provided a key and inadvertently added to the confusion by proposing a new arrangement of 9 species-groups for 29 species (some now synonyms), which became super-complicated. Verbeke (1961) renamed some of his 1950 groups, omitted some, added the testacea group and neavei subgroup, added new species to some groups, moved some species from the 1950 groups to the 1961 groups, and placed some species between groups, subsequent authors did not recognise his groups.

Knutson & Orth (2001) proposed nine groups for the world species of Sepedon , based on a non-cladistic analysis of 22 morphological features of adults and two behavioural features of larvae. The entire subgenus Parasepedon sensu Verbeke of the Afrotropical Region was placed by them together with seven Oriental and Australian-Oceanian species as the trichrooscelis group; the subgenus Mesosepedon formed the dispersa group; and the genus Sepedomyia formed the nasuta group. Clearly the subgeneric and group classification of Sepedon remains unresolved.

Because of this confusion and Verbeke’s (1950) misidentifications of species described by Loew, Becker and Adams, which further complicates the terminology, we do not recognize Verbeke’s groups of Parasepedon . However, we believe a new proposal of groups would be a useful result of an overall revision, and might also be useful as a starting point for a cladistic analysis of the subgenus Parasepedon . We add Sepedon (Parasepedon) straeleni Verbeke, 1950 (Sepedoninus) to the trichrooscelis group. Verbeke (1950) described Sepedoninus straeleni from one female from Kivu and misidentified males of S. straeleni as S. testacea Loew, 1862 . He noted that the “forceps” and aedeagus of specimens that he identified as S. testacea approach the form of S. (P.) trichrooscelis . Strangely, in his handwritten (Dec. 1968) notes on the draft of Knutson’s (1970) catalogue of Afrotropical Sciomyzidae Verbeke wrote “ straeleni is a synonym to [ Sepedoninus ] curvisetis Verb. (unpublished in my check list)”. This is clearly an error, but we mention this because it might help to explain Verbeke’s identifications of specimens in the collections of Brussels and/or Tervuren in his later publications (1961, 1962a, b, 1963).

Parasepedon Verbeke, 1950: 37 . Type species: Sepedon notambe Speiser, 1910 . By designation of Steyskal & Verbeke (1956).