Namadytes Hesse, 1969

Dikow, Torsten & Leon, Stephanie, 2014, Review of the genus Namadytes Hesse, 1969 (Insecta: Diptera: Mydidae: Syllegomydinae), Biodiversity Data Journal 2, pp. 1071-1071 : 1071

Namadytes Hesse, 1969

Namadytes Hesse, 1969: 278.

Namamydas Hesse, 1969: 284 junior synonym sensu Hesse 1972: 139 (ZooBank LSID).

Namadytes Namadytes vansoni Hesse, 1969 - Hesse 1969: 278.; Bowden 1980: 331. catalog

Description

Female genitalia (Fig. 1): densely arranged anteriorly directed setae present on T7-8 and S7-8; T8 with broad anterior rectangular apodeme; T9 formed by wide, rectangular sclerite with median protuberance; T9+10 entirely fused, T10 divided into 2 heavily sclerotized acanthophorite plates, 8-10 acanthophorite spines per plate; 2 spermathecae, all equally large, formed by ± expanded heavily sclerotized ducts; individual spermathecal duct short; S9 (furca) formed by 1 sclerite, ring–like (joined anteriorly and posteriorly), anterior furcal apodeme present, 2 lateral projections forming divided apodeme, lateral furcal apodeme present, median furcal bridge absent.

Male terminalia (e.g., Fig. 2) T1-7 well-developed, entirely sclerotized, T8 postero-medially weakly sclerotized, with anterior transverse sclerotized bridge connecting lateral sclerites; T7-8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation postero-medially, S8 simple plate, entire (undivided) ventro-medially, not fused to T8 dorso-laterally; epandrium formed by single sclerite (fused medially ± entirely), distally in dorsal view blunt, evenly rounded; subepandrial sclerite without lateral or median protuberances; hypandrium strongly concave, cup-shaped, entirely sclerotized ventrally (forming a single sclerite), entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex, supra-hypandrial sclerite absent; gonocoxite dorso-ventrally flattened in distal ½, higher in proximal ½, without median or lateral protuberance, gonocoxal apodeme absent; 2 functional aedeagal prongs, short and wide, medio-distally connected; aedeagal epimere absent; lateral ejaculatory process present, large cylindrical sclerite; ejaculatory apodeme formed by single dorso-ventrally oriented plate; ventro-median margin of dorsal aedeagal sheath heavily sclerotized (appearing entirely closed); dorsal aedeagal sheath long, sperm sac entirely covered; sperm sac appearing ± heavily sclerotized.

Diagnosis

The genus (Fig. 3) is distinguished from other Syllegomydinae by the structures of the male genitalia (aedeagal prongs fused medially), the presence of a V-shaped indentation on the dorso-median antepronotum, and the presence of a tuft of setae on the infra-halter sclerite (ventral to halter base and posterior to metathoracic spiracle), with the exception of females of one species. Furthermore, flies are relatively small with a wing length of 6.6-14.2 mm and the males exhibit a yellow to light brown abdomen, which is unusual for southern African Mydidae .

Distribution

Namadytes is distributed in southern Africa and restricted to Namibia and north-westernmost South Africa (Fig. 4).

Taxon discussion

Males are unique in the arrangement of their medially fused aedeagal prongs and the yellow to light brown abdominal coloration. Females in contrast are more generalized and similar to other female Mydidae occurring in southern Africa. However, the antero-median V-shaped indentation on the antepronotum and the presence of white setae on the infra-halter sclerite are relatively easy to observe and distinguish the females from other Mydidae . There is considerable sexual dimorphism and the setation, for example on the anatergites, is always easier to observe in males. Intra-specific variation in the abdominal coloration, especially in females, is likewise substantial, which probably led Hesse to describe a species twice.