Six new species of Microdon Meigen from Madagascar (Diptera: Syrphidae) Author Reemer, Menno Author Bot, Sander text Zootaxa 2015 4034 1 127 147 journal article 10.11646/zootaxa.4034.1.6 6d5f5483-6698-4c30-bedd-84a4625c8bc3 1175-5326 243180 F4D27705-2963-4CBF-A3A3-017BAAB69C25 Key to Madagascan species of Microdon Only males are known of Microdon berobaka Reemer sp. n. , M. janne Bot sp. n. and M. tsara Keiser , so whether this key also works for females of those species is unknown. 1 Occiput evenly narrow over entire length: dorsal eye margin parallel to hind margin of head ( Figs 52 , 59 ). Male hind basitar- somere dorsally with wide and deep longitudinal groove ( Fig. 5 ). Male genitalia: phallus furcate far from apex, very slender ( Figs 53 , 61 )....................................................................... Microdon ( Megodon ) 2 - Occiput dorsally widened (even if only slightly): dorsal eye margin diverging from hind margin of head ( Figs 21 , 47 ). Male hind basitarsomere dorsally without longitudinal groove (Fig. 6). Male genitalia: phallus furcate closer to apex, moderately slender ( Figs 10 , 15 , 23 , 29 , 35 , 40 , 48 )......................................................... Microdon s.l. 3 2 Larger species:> 10 mm . Scutellar calcars very large and conical, making angle of about 30° with mesoscutum in lateral view ( Figs 57, 60 )....................................................................... M. stuckenbergi (Keiser) - Smaller species: < 10 mm . Scutellar calcars more slender and more or less at same level as rest of scutellum ( Figs 54 , 55 )....................................................................................... M. planitarsus Keiser 3 Most of body with bronze sheen ( Figs 30 , 45 ). Scutellar calcars of 1/3 of scutellar length or longer..................... 4 - Body largely without bronze sheen, at most mesonotum and tergites 3–4 faintly metallic ( Figs 16 , 18 , 32 , 36 , 41 , 44 ,). Scutel- lar calcars less than 1/3 of scutellar length.................................................................. 5 4 Tibiae orange ( Fig. 45 ). Alula bare on basomedian 1/2............................................ M. tsara Keiser - Tibiae black, except apices somewhat paler ( Fig. 27 ). Alula entirely microtrichose................ M. irwini Reemer sp. n. 5 Ventrolateral part of face black, contrasting with pale rest of face ( Figs 13 , 17 )............... M. harinhalai Reemer sp. n. - Face more or less unicolorous, without contrasting parts ( Figs 9 , 20 , 25 , 34 , 38 ).................................... 6 6 Pleuron and tergites black ( Figs 32, 33 )..................................................... M. janne Bot sp. n. - Pleuron at least partly pale brown, tergites partly brownish ( Figs 7, 8 , 18, 19 , 24 , 36 , 37, 41 , 42)....................... 7 7 Tergite 3 with complete fascia of pale golden pile along posterior margin ( Fig. 7 ).............. M. berobaka Reemer sp. n. - Tergite 3 at most with medially widely interrupted, narrow fascia of pale pile posterolaterally......................... 8 8 Smaller species ( 11 mm ) with more compact abdomen ( Fig. 18 ). Lateral margins of tergites 3 and 4 with long white pile ( Fig. 22 ). Male genitalia as in Fig. 20 .................................................... M. ifanadiana Reemer sp. n. - Larger species ( 13–14 mm ) with more elongate abdomen ( Fig. 36 ). Lateral margins of tergites 3 and 4 with short yellowish pile ( Fig. 39 ). Male genitalia as in Fig. 40 ................................................. M. sava Reemer sp. n. 1 2 4