Talahua is very similar to Argentinomyia species, but differs by having the metacoxa with pile posteromedially on apical angle (bare in Argentinomyia). Talahua has the faces straight, not produced, metasternum entire, not reduced, antennal pits separated, abdomen with parallel sides, anterior anepisternum and metaespiternum bare, metasternum bare, male genitalia very large with
elongate cerci and surstyli, and face and scutellum black.
Talahua fervida was described as a new subgenus of Melanostoma (tribe Melanostomini). Later, Thompson et al. (1976) considered it as a different genus.
Talahua fervida (Fluke, 1945).
Fluke, C.L.,Jr. (1945) The Melanostomini of the Neotropical Region (Diptera, Syrphidae). American Museum Novitates 1272, 29 pp.
Adapted from original description (Fluke 1945).
A large species; face perpendicular with a well-rounded tubercle; basoflagellomere large and rounded; abdomen with prominent yellow maculae; genitalia of male elongate.
MALE.
Head large, wider than the thorax and abdomen; covered with yellowish gray pollinosity, shining black on the prominent round tubercle, oral tips, ocellar triangle, and a large triangular macula on the front; sides of face with a faint, slightly rugose area; pile on front black, on gena and face yellow, on ocellar triangle black, on the occiput yellow except the dorsal pile, which are black. Antennae black, pedicel and the lower basal corner of basoflagellomere red; arista bare, black.
Thorax black, the scutum shining, covered with yellow pollen and short golden pile with many longer black pile that appear yellowish at the base; these pile become longer posteriorly and longer on the scutellum, which has a deep groove next to the rim (emarginate), fringe of scutellum yellow; pleura yellow pollinose and pilose. Legs black; profemora yellow on the apical two-thirds, mesofemora on the apical third, metafemora on the extreme apex; all the tibiae yellow with a dark ring near the middle, more prominent on the metalegs; the pile yellow, black on the metatibia and above on the tarsi. Wings smoky; the stigma brown; calypter and plumule yellow; halter yellow, with a darkened capitulum.
Abdomen elongate, black, with four pairs of lateral yellow maculae; first tergum shining, second with the broad lateral yellow and only the apex black, third with similar but wider maculae, fourth with still wider but less elongate maculae, fifth with a pair of small maculae in the basal corners. Pile yellow on the sides basally, black down the middle and on the apical terga. Genitalia very large, the surstyli long and black, the cerci elongate and yellow.
FEMALE.
Very similar but the abdominal maculae are somewhat shorter. Front narrow above, not the much wider than ocellar triangle, shining above with a pollinose band below.
unless otherwise stated