Baccha grata, Curran, 1941

Mengual, Ximo, Miranda, Gil Felipe G. & Thompson, F. Christian, 2018, Unraveling Ocyptamus and the Baccha legacy (Diptera: Syrphidae): redefinition of groups and new species descriptions, Zootaxa 4461 (1), pp. 1-44 : 20

grata Curran, 1941 [incertae sedis]

Figs 40–43 .

Baccha grata Curran, 1941: 270 . Type-locality: Brazil, Mato Grosso, Chapada [HT ♀ AMNH].

Ocyptamus gratus . Thompson et al. (1976: 19).

Comments. After studying specimens at the CNC identified as grata Curran , the male genitalia and wing characters are similar to the ones of placiva and conjunctus (see comments below in placiva ). The abdominal markings are similar to those two species, but grata has an only slightly petiolate abdomen and its basoflagellomere is remarkably bifurcated in both sexes (a character seen so far in species of the subfamily Microdontinae and in the genus Cacoceria Hull of the Eristalinae ). Other unique characters of this species are the male abdominal segment 5 and genitalia flexed dorsally, positioned perpendicular to the rest of the abdomen, tergum 4 with deep concave apical margin and sternum 4 with pair of acute projections apically. The female terga 5 and 6 are slightly asymmetric. It is unfortunate that when Curran (1941) described this species his type specimen lacked its most distinctive attributes, i.e. the basoflagellomere and the apex of the abdomen, partly destroyed by pests.

Figures

FIGURES 38–45. 38: Syrphus sargoides Macquart [male, DZUP-Diptera 342599], habitus, dorsal view. 39: Syrphus sargoides [female, GFGM-MNRJ0003], metafemur and metatibia, lateral view. Scale = 1 mm. 40: Baccha grata Curran [male, USNMENT 00022542], habitus, lateral view. Scale = 2 mm. Note: framed with white, a zoom-in of the antennae. 41: Baccha grata [male, USNM], male, habitus, lateral view. 42: Baccha grata [male, USNM], male, habitus, dorsal view. 43: Baccha grata [female, USNMENT 00022543], spermatheca. Scale = 100 µm. 44: Syrphus conjunctus, female, by Steve Marshall. 45: Ocyptamus dimidiatus (Fabricius) [female, INPA-DIP0000808], antenna. Scale = 0.2 mm. Note: Arrow indicates the narrow pedicel projection over the basoflagellomere.