Key to the genera and subgenera of Afrotropical syrphine flower flies A. Postpronotum pilose (Fig. MND 64); male abdomen with tergum 5 not visible dorsally (Fig. MND 101) (subfamilies Microdontinae & Eristalinae).................................................................... other flower flies - Postpronotum bare (Fig. MND 65); male abdomen with tergum 5 visible dorsally (Fig. MND 97) (subfamily Syrphinae).... 1 1. Tergum 1 greatly reduced, frequently almost linear on disc and practically covered by scutellum, sublaterally at most 1/2 as long as tergum 2 (Fig. MND 96); terga not punctate; length 6.7 mm or more....................................... 5 - Tergum 1 well-developed, especially on disc where it is frequently 1/2 as long as tergum 2 and always extends well beyond scutellum, sublaterally about 3/4 as long as tergum 2 (Fig. MND 97); terga minutely punctate; length 7.5 mm or less................................................................................................... Paragus ...2 2. Eye with pile of nearly uniform color, not forming vittae of contrasting color; scutellum entirely black... Pandasyopthalmus - Eye with pile arranged in 2–5 more or less vertical vitta or contrasting color; scutellum black with apex narrowly yellow or reddish.............................................................................................. 3 3. Scutellum with conspicuous dentis (teeth) on posterior margin; eye in dorsolateral view with two dark and three more distinct white pile fasciae.......................................................................... Serratoparagus - Scutellum with apical margin simple, without dens; eye with two white pile fasciae among dark pile.................... 4 4. Terga 1–5 completely fused, at least laterally...................................................... Afroparagus - Only terga 1–2 fused completely................................................................... Paragus 5. Abdomen parallel-sided (Fig. MND 96) to oval, never distinctly petiolate......................................... 7 - Abdomen elongate, strongly petiolate (Fig. MND 95); 2nd tergum narrower than 3rd tergum.......................... 6 6. Laterotergum pilose, at least with a patch of long pile dorsally; postpronotum and/or anterior anepisternum pilose; metepisternum pilose; scutum usually with a well-develop collar of longer pile on anterior margin...................... Allobaccha - Laterotergum, anterior anepisternum, metepisternum all bare; scutum without pile collar........................................................................................................................ Pseudodoros *** Baccha in our sense does not occur in the Aftropical region, but would run here in this key and is separate from the preceeding genera by a complete metacoxal bridge. 7. Face and scutellum entirely black in background color; abdomen usually without marginal sulcus; metasternum bare; eye bare. Note that one Pelloloma species has an indistinct marginal sulcus on the apical tergum 5............................ 22 - Face or scutellum or both at least partly yellow or yellowish brown in background color, both never entirely black, if in doubt, eye pilose; abdomen, metasternum, and eye variable.......................................................... 8 8. Antenna short, shorter than head; basoflagellomere at most twice as long as broad; scape and pedicel not longer than broad (Fig. MND 7–8)...................................................................................... 10 - Antenna elongate, longer than head; basoflagellomere at least three times as long as broad; scape or pedicel longer than broad (Fig. MND 4)......................................................................................... 9 9. Metafemur and metatibia without pile brushes; eye densely long pilose; scape and pedicel subequal; abdomen strongly convex dorsally, strongly margined; vein R 4+5 sinuate, looped into cell R 4+5; calypter bare......................... Chrysotoxum - Metafemur and metatibia with brushes of long pile; eye sparsely and short pilose; scape about 3 times as long as pedicel; abdomen not convex nor with marginal sulcus; vein R 4+5 straight; calypter pilose on ventral lobe.................. Afrosyrphus 10. Calypter with lower lobe pilose, especially on posteromedial portion (Fig. MND 62); metacoxa with a tuft of strong pile at posteromedial apical angle (Fig. MND 77)........................................................... Betasyrphus - Calypter bare; metacoxa without pile tuft.................................................................. 11 11. Anterior anepisternum bare; wing margin without minute closely spaced black maculae on posterior margin............. 13 - Anterior anepisternum pilose at least posterodorsally (Fig. MND 65); wing margin with a series of minute closely spaced black maculae on posterior margin (Fig. MND 61)............................................................... 12 12. Metasternum pilose; metepisternum pilose ventrad to spiracle......................................... Episyrphus - Metasternum bare; metepisternum bare............................................................ Meliscaeva 13. Abdomen without marginal sulcus....................................................................... 19 - Abdomen with at least a weak marginal sulcus on terga 4 and 5, often with a strong sulcus on terga 3–5................ 14 14. Metapleuron bare ventrad to spiracle; metasternum variable; size and shape variable............................... 16 - Metapleuron with a tuft of fine pile ventrad to spiracle; metasternum pilose; large species with broad flattened abdomens with distinct marginal sulcus................................................................................ 15 15. Mesonotum anteriorly with a distinct collar of longer and denser pile; vein R 4+5 sinuate, distinctly looped into cell R 4+5 ................................................................................................... Asarkina - Mesonotum without a collar of pile; vein R 4+5 nearly straight........................................... Achoanus 16. Eye densely pilose; metacoxa with tuft of strong pile at posteromedial apical angle (Fig. MND 77)............ Betasyrphus - Eye bare; metacoxal without such a pile tuft............................................................... 17 17. Metasternum pilose; wing densely microtrichose on apical 1/3; scutum dark laterally; male metacoxa simple...... Eupeodes - Metasternum bare; wing extensively bare, with only sparse scattered microtrichia on apical 1/3...................... 18 18. Scutum with well-defined bright yellow lateral vitta, extending from postpronotum to scutellum; male metacoxa with ventral spine-like process (widespread)................................................................... Ischiodon - Scutum with ill-defined yellow lateral vitta; male metacoxa simple (northern Chad only)........................ Scaeva 19. Scutum with lateral yellow vitta extending from postpronotum to scutellum...................................... 21 - Scutum with lateral yellow vitta not extending beyond transverse suture......................................... 20 20. Face with broad black vitta; subscutellar fringe well-developed except on medial 1/3; male genitalia small, with tergum 9 at most 1/2 as wide as abdomen; female 5th tergum with distinct yellow maculae which are isolated from lateral margins................................................................................................. Exallandra - Face yellow; subscutellar fringe absent; male genitalia large and globose, with tergum 9 as wide as abdomen; female 5th tergum either without yellow maculae or yellow maculae broadly reaching lateral margin.............. Sphaerophoria (s. s.) 21. Subscutellar fringe complete, dense; male holoptic; male genitalia small, inconspicuous, with tergum 9 at most 1/2 as wide as abdomen; female face without carina (widespread, but not St. Helena).................................... Allograpta - Subscutellar fringe absent; male dichoptic; male genitalia large and globose, with tergum 9 as wide as abdomen; female face with a distinct median carina extending from antenna to tubercle (St. Helena only)......... Sphaerophoria (Loveridgeana) 22. Metepisternum with some fine subappressed pile; katepisternum with pile patches broadly separated posteriorly, joined anteriorly (Fig. MND 42); metacoxa with tuft of pile at posteromedial apical angle (as in Fig. MND 48)................................................................................................ Xanthandrus (Afroxanthandrus) - Metepisternum bare; katepisternal pile patches broadly separated throughout (as in Fig. 45); metacoxa with or without pile tuft ................................................................................................... 23 23. Metacoxal with tuft of pile at posteromedial apical angle (as in Fig. MND 48); metafemur swollen, usually about 3 times as broad as tibia; metasternum entire................................................................. Pelloloma - Metacoxa without posteromedial apical pile tuft; metafemur simple, not swollen, about as broad as tibia................ 24 24. Metasternum greatly reduced, with deep posterior incision laterally so that sclerotized portion consists of a median diamond-shaped area with narrow anterior and lateral strips (Fig. MND 70); face not produced below, with small tubercle (Fig. MND 8)................................................................................... Melanostoma - Metasternum entire (Fig. MND 71); face almost straight with strong tubercle (Fig. 1B), slightly produced forward ventrally.............................................................................................. Afrostoma

Published as part of Thompson, F. Christian & Skevington, Jeffrey H., 2014, Afrotropical flower flies (Diptera: Syrphidae). A new genus and species from Kenya, with a review of the melanostomine group of genera, pp. 97-114 in Zootaxa 3847 (1) on pages 101-102, DOI: 10.11646/zootaxa.3847.1.5, http://zenodo.org/record/4928795