T. antennatum is the genitype of Tuberculanostoma. This species is similar to T. cilium, both with dichoptic males and profemora without curled bristles, but differs by having the facial tubercle nearer antennae base than the oral tip and the male genitalia large, with long, slender surstyli.
Tuberculanostoma antennatum Fluke, 1943.
Fluke, C.L.,Jr. (1943) A new genus and new species of Syrphidae (Diptera) from Ecuador. Annals of the Entomological Society of America 36, 425-431.
Adapted from original decription (Fluke 1943).
Shining blue black, the antennae extending to the tips of the oral margin, eyes of the male dichoptic, genitalia large with long curved surstyli.
MALE.
Head shining blue black with a rather large frontal triangle which is lightly white pollinose but with black bristly pile. Face well protruding forward, but not at all downward; a very prominent tubercle, which is closer to the antennal base than to the oral tips; sides of the face and gena very lightly white pollinose and with white pile. Eyes distinctly dichoptic. Ocellar triangle and upper occiput black with long black pile. Antennae elongate, basoflagellomere equal to scape and pedicel together, the scape slightly longer than the pedicel; basoflagellomere distinctly constricted on the basal third; arista basal, about the same length as thebasoflagellomere, briefly pubescent.
Thorax everywhere shining blue black; pile of the scutum black, the scutellum black on the disc, but with white pile along the margins; at the apex two widely separated rather long, slender black bristles; on each side of these terminal pile there are often three or four more although they are usually shorter; subscutellar fringe short, thin and white. Pile of the pleura sparse but practically all white. Legs everywhere black and the pile mostly whitish except on the mesotibia where it is short and black. The pile on the dorsal sides of the tarsi are usually black. On the under sides of the metatarsus, the pile form almost a thick yellowish mat. Wings hyaline, blackish toward the base, the stigma yellowish. The costal margin with a fringe of short, black bristle-like hairs. Calypter white with yellowish fringe; plumula very much abbreviated, yellowish-brown in color; halteres yellow, the stem brown.
Abdomen everywhere shining bluish-black. The pile practically all whitish, becoming black on the genitalia; the genitalia are quite large and the surstyli are extremely long and slender. In the preserved specimens, the abdomen has a constricted appearance at the apex of the third tergum; at the point of extreme constriction, the abdomen is only half or one-third as wide as at the apex of the second tergum.
FEMALE.
Very similar to the male; the front rather wide, about three times as wide as the ocellar triangle and becoming considerably wider across the antennae; the pile all black. Antennae slightly shorter than on the male and the basoflagelloemre not so conspicuously constricted. Abdomen more oval, but very highly polished blue-black.
Different authors have either combined the tribes Melanostomini and Bacchini or treated them as separate, and the taxonomic concept of the tribes has varied among authors. Genera Melanostoma, Xanthandrus, Tuberculanostoma and Platycheirus were the members of Melanostomini for Hull (1949), and close to them there was Rohdendorfia.
unless otherwise stated