Mesorhaga, SCHINER, 1868

Grichanov, I. Ya., 2021, A new species the genus Mesorhaga Schiner, 1868 (Diptera: Dolichopodidae) from Tanzania, with a key to Afrotropical species, Far Eastern Entomologist 435, pp. 1-6 : 3

Key to Afrotropical species of Mesorhaga

( M. africana is known by female only)

1. M 1+2 with gentle curvation; dm-m distinctly shorter than distal part of M 4 …..................... 2

– M 1+2 with two nearly right-angular bends; dm-m usually as long as distal part of M 4 ......... 5

2. Cercus thick and short, about 1/4 length of epandrium, without very long setae ( Grichanov, 2000: fig. 1); hind tibia yellow, with narrow brown posterodorsal stripe on second quarter; body 2.4–2.6 mm ( Namibia) ....................................... M. kirkspriggsi Grichanov

– Cercus about half as long as epandrium, with at least 3 very long dorsolateral setae; hind tibia yellow or black at extreme apex ................................................................................ 3

3. Cercus weakly curved, with 3 dorsolateral setae, shorter than cercus ( Grichanov, 1997: fig. 1); distal part of M 4 1.5 times longer than dm-m; hind femur brown, hind tibia and basitarsus yellow; body 3.7 mm ( Tanzania) ............................... M. mahunkai Grichanov

– Cercus hooked, with at least 4 dorsolateral setae, longer than cercus; distal part of M 4 1.3 or 1.7 times longer than dm-m; hind femur mostly yellow ................................................... 4

4. Distal part of M 4 1.7 times longer than dm-m; femora and tibiae yellow, hind femur with small brown spot at apex, apical segments of tarsi brown; hypopygium ( Grichanov 1999: fig. 1); body 4 mm ( DR Congo, Kenya) ....................................... M. garamba Grichanov

– Distal part of M 4 1.3 times longer than dm-m; femora mostly yellow, hind femur with brownish apices, fore and mid femora brown in basal third; hind tibia black at extreme apex; hind basitarsus black-brown; hypopygium ( Grichanov, 1998: fig. 3); body 4.7–5.3 ( Burundi) ....................................................................................... M. tsurikovi Grichanov

5. Antenna yellow; legs almost entirely yellow; cercus with very long dorsolateral setae, longer than cercus ( Fig. 1A–E ); body 7.3 mm ( Tanzania) ............. M. tanzaniensis sp. n.

– Antenna black; legs mostly brown or black; cercus without very long setae; body shorter than 4 mm .......................................................................................................................... 6

6. Hind femur brownish except yellow apex, hind tibia dark-yellow except brownish apex, hind basitarsus brownish; dm-m about as long as distal part of M 4 (Curran, 1927: fig. 16); body 2.25 mm ( DR Congo, Tanzania) ................................................ M. africana Curran

– Hind leg entirely black; dm-m as long as or shorter than distal part of M 4; body 3.3–3.8 mm ............................................................................................................................................ 7

7. Legs black with fore tibia brown; dm-m 2/3 as long as distal part of M 4; hypopygium ( Grichanov, 1998: fig. 2); body 3.3 mm ( Madagascar) ............. M. pauliani Vanschuytbroeck

– Fore and mid tibiae and basitarsi yellow; dm-m as long as distal part of M 4; hypopygium ( Grichanov, 1998: fig. 1); body 3.8 mm ( DR Congo, Madagascar, South Africa) ............ ........................................................................................................ M. demeyeri Grichanov

Figures

Fig. 1. Mesorhaga tanzaniensis sp. n. (holotype): A – head; B – antenna; C – wing; D –