Male
Sepsis pyrrhosoma. Male alcohol-vouchered specimen.
Deposited at: Evolutionary Biology Laboratory, National University of Singapore (Singapore)
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Diagnostic illustrations for adults
Adapted from:
Tan DSH, Ang Y et al. (2010). From cryptic species to integrative taxonomy: an iterative process involving DNA sequences, morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera). Zoologica Scripta 39(1): 51-61.
Adult Sepsis pyrrhosoma resemble lightly coloured specimens of Sepsis flavimana. However, S. pyrrhosoma can be consistently distinguished from the latter by the following characters. While S. flavimana is always black to dark brown in thorax and head colour, S. pyrrhosoma is mostly reddish to yellow on the pleura and abdominal sections as well as on the face and gena. Fore-femora of S. pyrrhosoma are also consistently light yellow, while S. flavimana invariably retains a dark brown region dorsally. Colour is the only way to distinguish male S. pyrrhosoma from female S. flavimana morphologically. Additional characters in the male are: (1) the fore-tibial ventro-basal bump is always slight or non-existent in S. pyrrhosoma, bearing small, weak bristles, while S. flavimana has a distinct bump with longer and thicker bristles; The hypopygium of S. flavimana is entirely black with a smooth, beak-like surstylus while S. pyrrhosoma possesses a yellow hypopygium with only the surstylus darkened apically. (3) The S. pyrrhosoma surstylus bears sub-medial inward-facing protrusions not present in S. flavimana.
Source:
Tan, D. S. H., Y. Ang, et al. (2010). From ’cryptic species’ to integrative taxonomy: an iterative process involving DNA sequences, morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera). Zoologica Scripta 39(1): 51-61.
