Aphaniosoma notatum Collin, 1949

Ebejer, Martin J., 2023, The genus Aphaniosoma Becker, 1903 (Diptera: Chyromyidae) in the Eastern Mediterranean and Middle East, with descriptions of new species, European Journal of Taxonomy 872, pp. 1-161 : 116-119

Aphaniosoma notatum Collin, 1949

Fig. 67

Material examined

Holotype

EGYPT • ♂; Siwa Oasis; 18–19 Apr. 1935; J. Omer-Cooper leg., Armstrong College Expedition; NHMUK, B.M. 1935–354 , bar code 013435846 .

Remarks

Collin described this species from a single male. The figure given with the description ( Collin 1949: 141) readily identifies the relevant specimen as the holotype ( Fig. 67A ) and this was listed as such in Pont (1995: 118). Although the figure is accurate and Collin implied this species can be easily identified based on the hypopygial appearance, this is no longer the case because a similar appearance is sometimes seen in A. approximatum , A. gallagheri , A. proximum and A. scutellare Ebejer, 1998 . The “globular yellow processes below the yellow anal cerci” ( Fig. 67B ) are the dorsal halves of the divided epandrium (right and left) and the degree of their exposure beyond the margin of tergite 6 is variable, depending on the degree of abdominal shrinkage. Thus, they sometimes appear larger, sometimes smaller. Their colour is not reliable. The elongate, narrow, and apically curved postgonite is very similar in A. notatum and A. scutellare , and these may in fact be conspecific. The former has broader yellow markings on the abdomen, whereas the latter is much darker everywhere and with much narrower yellow outlines to sclerites except on the scutellum, which usually contrasts pale yellow and has broad black lateral margins. However, a completely grey thorax including the scutellum does occur in this species, suggesting a wide degree of variation that lends more support to this species and A. notatum being conspecific. Aphaniosoma scutellare has a distinctive pregenital sternite ( Ebejer 1998: 222, figs 69–70), but the shape of this structure in A. notatum is unknown and this could be a most helpful diagnostic character. The holotype being the only specimen representing this species, and since it is rather crudely and extensively glued to a pointed plastic mount, it is inadvisable to dissect it, risking complete destruction. It would be preferable to obtain more material from the type locality for further study of the hypopygium and so until such time, A. notatum and A. scutellare are considered separate species.

Distribution

Cyprus (doubtful), Egypt ( Collin 1949; Ebejer 2021a).

Figures

Fig. 67. Aphaniosoma notatum Collin, 1949, ♂, holotype (NHMUK, B.M. 1935–354, bar code 013435846). A. Habitus, lateral view. B. Hypopygium in situ, posterior view.