Namibimydas

Dikow, T., 2012, Review of Namibimydas Hesse, 1972 and Nothomydas Hesse, 1969 (Diptera: Mydidae: Syllegomydinae: Halterorchini) with the description of new species, African Invertebrates 53, pp. 79-111 : 105-106

Key to Namibimydas and Nothomydas species

(This key can also be accessed online at IdentifyLife.org and http://www.mydidae.tdvia.de/online_keys)

1 Alula well-developed, but medially not touching scutellum (when wings folded over abdomen); proboscis always long, extending beyond tip of postpedicel (Figs 41, 42); postocular macrosetae absent (occipital and postocular setae present); frons medially apubescent; small flies, wing length 5.5-8.9mm; ♀ with short, anterior directed setae on T4-8 (Figs40, 42) ( Nothomydas ) ... 5

- Alula well-developed and large, medially slightly overlapping with scutellum (when wings folded over abdomen); proboscis generally long, but not extending beyond tip of postpedicel (except in Namibimydas gaerdesi ) (Fig. 20); postocular macrosetae present (sometimes difficult to discern among dense occipital and postocular setae); entire frons pubescent; large flies, wing length 11.2-17.7mm; ♀ without short, anterior directed setae on T4-5 (these setae present on T7-8 though) (Figs 18, 20) ( Namibimydas ) ... 2

2 Metathoracic femora without antero- or posteroventral rows of macrosetae; parafacial area more than half the width of central facial gibbosity (at same level); distributed in coastal south-western South Africa (Fig.43) ... Namibimydas prinsi

- Metathoracic femora with well-developed antero- and posteroventral rows of macrosetae; parafacial area about half or less than half the width of central facial gibbosity (at same level); distributed in coastal and inland Namibia (Fig.43) ... 3

3 Proboscis short, not extending beyond fronto-clypeal suture; labellum about half of length of prementum; anatergite long white setose; abdominal setation short and sparse in♂ and ♀ (Figs 17, 18); distributed at eastern edge of Namib Desert sand dunes (Fig. 43) ... Namibimydas psamminos sp.n.

- Proboscis long, extending well-beyond fronto-clypeal suture (Figs 13, 20); labellum about quarter of length of prementum; anatergite asetose (absence of anatergal setae sometimes difficult to discern, view obfuscated by long white setae on katatergite and T1); abdominal setation long and dense in ♂ and ♀ (Figs 13, 19, 20); distributed in coastal Namib Desert (Fig.43) ... 4

4 Proboscis long, extending beyond tip of postpedicel (Fig. 13); mystax white to yellowish (Fig.13); wing veins yellow; postgena apubescent; known only from between Swakopmund and Sandwich Bay (Fig.43) ... Namibimydas gaerdesi

- Proboscis long, extending beyond fronto-clypeal suture, but not reaching tip of postpedicel (Fig. 20); mystax entirely white (Fig. 20); wing veins light brown; postgena lightly grey pubescent; known only from around Lüderitz (Fig. 43) ... Namibimydas stuckenbergi sp.n.

5 Scutum entirely apubescent (Fig. 35) ... 8

- Scutum predominantly grey pubescent, only anterior slopes (facing occiput) and sometimes sublateral and paramedian stripes apubescent (Fig. 38) ... 6

6 Vertex entirely grey pubescent; scutellum grey pubescent proximally, but apubescent distally ... ♀of Nothomydas picketti sp.n.

- Vertex medially apubescent, laterally grey pubescent; scutellum entirely grey pubescent ... 7

7 Postpedicel cylindrical in proximal third and symmetrically bulbous in distal two-thirds; scape and pedicel only white setose dorsally and asetose ventrally; T1 proximally apubescent and distally grey pubescent; parafacial area less than half the width of central facial gibbosity (at same level)....... Nothomydas gariepinus

- Postpedicel cylindrical in proximal quarter and symmetrically bulbous in distal three quarters; scape and pedicel white setose dorsally and ventrally; T1 entirely apubescent; parafacial area about as wide as half the width of central facial gibbosity (at same level) ... Nothomydas namaquensis

8 T1-5 entirely apubescent, T6-7entirely grey pubescent (Fig.41); scutellum entirely apubescent; metathoracic tarsomere 1 less than combined length of tarsomeres 2-3 ... ♂of Nothomydas picketti sp.n.

- T1 apubescent, T2-7 posteromedially grey pubescent otherwise apubescent (Fig. 35); scutellum grey pubescent proximally and apubescent distally; metathoracic tarsomere 1 as long as combined length of tarsomeres 2-3 ... Nothomydas aquilonius sp.n.