Serichlamys Curran, 1925:50

Differential diagnosis of Serichlamys

females generally larger than males. Serichlamys species are mostly dark coloured hoverflies with a more or less oval abdomen. The following combination of characters is unique to this genus:

eye bare (setulose in Laetodon Reemer, 2013);

Wing: vein R4+5 with posterior appendix extending into cell r4+5 (Fig. 1) (without such appendix in several other genera of Microdontinae);

postero-apical corner of cell r4+5 more or less rectangular or somewhat acute (Fig. 1) (widely rounded in Microdon and Peradon Reemer, 2013);

postpronotum setulose (bare in e.g., Surimyia Reemer, 2008 and certain species of Peradon);

anepisternum with large bare part medially (Figs 2, 4) (entirely setulose in Metadon Reemer, 2013);

proepisternum setulose (Figs 2, 3) (bare in Archimicrodon and many other genera);

tergites 3 and 4 fused, not able to articulate independently (not fused in Ceratophya Wiedemann, 1830).

Species of Serichlamys look somewhat similar to those of the Old World genus Archimicrodon, with which they share most of the characters mentioned above. However, Serichlamys always differs in the presence of setulae on the proepisternum (bare in Archimicrodon). In general, the antennae of Serichlamys species are longer than those of Archimicrodon species (a character used in the key of Reemer and Ståhls 2013a), but there is considerable overlap, so this character is unreliable. In Archimicrodon the structure of the male genitalia is rather uniform across the species, with both phallus and surstylus generally of similar shape in all known species (Reemer and Ståhls 2013a: figs 22–26), whereas among species of Serichlamys there is much more variation (Figs 138–154). Serichlamys species also differ from Archimicrodon species in the presence of clearly defined patterns of dull and shiny areas on the tergites (in Archimicrodon the tergites are more uniformly shiny or dull). Interestingly, in a few Serichlamys species (e.g., S. spathulata Reemer, sp. nov.) the scutellar calcars are ‘spoon-shaped’, as in certain Afrotropical species of Archimicrodon (subgenus Hovamicrodon Keiser, 1971).