Baccha placiva, Williston, 1888

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

placiva Williston, 1888 [incertae sedis]

Figs 71, 75, 77 .

Baccha placiva Williston, 1888: 269 . Type-locality: Brazil, Mato Grosso, Chapada [LT ♂ AMNH] . Lectotype ♂ here designated.

Ocyptamus placivus . Thompson et al. (1976: 25).

Hybobathus placivus . Miranda (2017: 55).

Comments. Baccha placiva Williston was described from a male and a female. A male deposited in the AMNH and labeled “Chapada” “ TYPE // No. // A.M.N.H.” [red] “S.W. Williston // Collection” “Am. Mus. Nat. Hist. // Dept. Invert. Zool. // No. 19166 ” “ Lectotype // Baccha placiva Williston // Des. G.F.G. Miranda, 2017 ” is here designated lectotype and has been so labeled. This lectotype designation is made in order to fix the concept of placiva and to ensure universal and consistent interpretation of the same.

Morphological evidence brings this species close to conjunctus Wiedemann and grata Curran. Besides the similar scutum and abdominal pattern, and the mostly hyaline wing with slightly sinuous veins R4+5 and M1, male genitalia have a more sclerotized phallus and have lateral lobes on the hypandrium, as in those two other species. The evidence is still weak to support a taxon comprising these three species; furthermore, placiva has a regular antenna when compared to the other two species.

Figures

FIGURES 71–77. 71: Baccha placiva Williston [male, GFGM-CZMA0002], habitus, dorsal view. Scale = 3 mm. 72: Mimocalla capitata (Loew) [male, USNMENT 00037907], habitus, dorsal view. 73: Hybobathus lineatus (Macquart) [male, USNM], habitus, dorsal view. 74: Mimocalla capitata [male, USNMENT 00037907], habitus, lateral view. 75: Baccha placiva [male holotype, AMNH, No. 19166], by the AMNH. 76: Mimocalla erebus (Hull) [male, CNC_Diptera209355], male genitalia, lateral view: c: cercus; e: epandrium; s: surstylus. 77: Baccha placiva [male, GFGM-MPEG0006], male genitalia, lateral view: c: cercus; e: epandrium; s: surstylus.