Eosalpingogaster and Salpingogaster are readily distinguished from all other syrphine groups by the presence of distinct black spinose bristles on the metafemur combined with the petiolate abdomen and sinuate vein R4+5. Both genera have petiolate abdomens, but Salpingogaster is distinguished from Eosalpingogaster by the much more greatly sinuate vein R4+5; other syrphines with sinuate vein R4+5 have oval abdomens. Eosalpingogaster has 1st tergum not produced into a spur, vein R4+5 only slightly sinuate and occipital cilia in 3–4 rows dorsally. In contrast, Salpingogaster has 1st tergum produced laterally into a strong spur and occipital cilia reduced to a single row dorsally.
Salpingogaster pygophora has yellow face, notopleuron and posterior anepisternum yellow, katepisternum dark with dorsal long broad yellow macula, 3rd tergum unicolour, wing entirely microtrichose, katatergum and katepimeron black, frons with medial black macula, isolated by yellow from eye, and male genitalia with long hook-shaped process.
Salpingogaster pygophora Schiner, 1868.
Schiner, I.R. (1868) Diptera. vi + 388 pp., 4 pls. In [Wullerstorf-Urbair, B. von (in charge)], Reise der osterreichischen Fregatte Novara. Zool. 2(1)B. K. Gerold's Sohn, Wien. [1868.04.30]
New description:
MALE.
Head: Face with facial tubercle, oral margin close to the tubercle, entirely yellow, yellow pilose; gena yellow; lunule dark; frontal triangle yellow with medial dark macula not reaching lateral margins, black pilose; dichoptic, eye bare; vertical triangle narrow, black, black pilose, with ocelli close to anterior margin; antenna yellow, black pilose, basoflagellomere orangish; antennae on protuberance, distinct in profile; occiput black, silver pollinose, mainly yellow pilose, black pilose dorsally.
Thorax: Scutum dark brown to black, yellow anteriorly, with postpronotum, notopleuron and postalar callus yellow, with two dorsomedial broad bronze pollinose vittae, golden yellow pilose laterally; postpronotum bare; scutellum yellow with diffuse brownish medial macula, short dark pilose, subscutellar fringe absent. Pleuron mostly black, except anterior and posterior anepisternum yellow, anterior anepimeron yellow and katepisternum with large dorsal yellow macula; metasternum bare; postmetacoxal bridge complete; dorsal calypter yellow, ventral calypter brownish; plumula absent; halter yellowish; spiracular fringes yellowish. Wing: Wing membrane hyaline, with anterior margin and basal area (before vein h) yellow, veins in this area also yellow, and with anterior margin apically dark brown to black, from stigma to end of vein R2+3; stigma bicolour, yellow basally and dark apically; vein M1 strongly sinuated and vein R4+5 strongly sinuated into cell dark brown R4+5; entirely microtrichose. Alula bare, narrow, as broad as costal cell. Legs: Femora with ventral spinose bristles; all coxae and trochanters black, pro- and mesolegs yellow; metafemur yellow with basal brownish to dark brown area and subapical orangish-brown ring; metatibia yellow, orangish on apical 2/5; metatarsi orangish.
Abdomen: Strongly and distinct petiolate, with tergum 2 cylindrical and narrower than thorax, tergum 3 broadening gradually posteriorly, unmargined. Tergum 1 produced laterally into a strong spur, yellow with orange fascia on posterior margin; tergum 2 orange with two basolateral yellow maculae; terga 3 to 8 entirely orange; sterna orange except sternum 1 yellow; sternum 4 with posterior margin produced laterally into two projections; male genitalia large, sternum 8 modified with long bifid hook-shaped process.
FEMALE.
Similar to male except frons yellow with brownish macular dorsad to antennae extending posteriorly and reaching black ocellar area, very narrow medially with broad lateral yellow margins. Abdomen in females more flat without modifications in sternum 4.
The group was first recognized and named by Walker (1852: 223). Unfortunately his description was brief and his name, Amathia, was preoccupied. Walker did note the two critical characters for the group, the sinuate vein R4+5 and spines on the femora. Schiner (1868: 344) subsequently re-described the genus and provided the name, Salpingogaster.
Mengual et al. (2008) included several Salpingogaster species in their molecular phylogeny. The genus was recovered as monophyletic in two different positions using different weighting schemes: as a sister group of Asarkina, Meliscaeva, Episyrphus, Allograpta, Sphaerophoria and Exallandra (1:1, gap:indel); or as a sister group of Allograpta, Sphaerophoria and Exallandra (2:1, gap:indel).
unless otherwise stated