Mesorhaga tanzaniensis Grichanov, 2021

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 : 3-5

Mesorhaga tanzaniensis Grichanov , sp. n.

http://zoobank.org/NomenclaturalActs/ C042E95F-8A0F-40CB-BCCF-2D435A50C635

Fig. 1A–E

TYPE MATERIAL. Holotype – ♂ (dried from ethanol and mounted on pin),

Tanzania: Morogoro Region, Udzungwa Mt. Nat. Park, Mito Mitatu , 7°50´22.7´´S ,

36°50´42.8´´E, 1325 m, Malaise trap No 3, 7.X 2013, leg. T. Pape & N. Scharff

[ ZMUC].

DESCRIPTION. MALE. Head ( Fig. 1A ). Frons shining greenish blue, densely covered with white pruinosity; 1 white hair-like vertical seta and 2 strong postvertical setae present at end of postocular row; upper postocular setae black, short, uniserial;

ventral postcranium covered with irregular white hairs; face and clypeus metallic green with bronze reflections and dusting of silvery pruinosity; face broad, about as high as wide under antennae, narrowed downward, 3 times higher than clypeus;

clypeus small, adjacent to margin of eyes; antenna ( Fig. 1B ) with scape and pedicel small, simple, light yellow; pedicel with ring of short yellow setae, 1 longer yellow ventral and 1–2 longer black dorsal bristles; postpedicel yellow, small, conoid, as long as high, with short hairs; arista-like stylus brown, dorsoapical, separated from postpedicel, microscopically haired; length (mm) of scape, pedicel, postpedicel,

stylus (segments 1 and 2), 0.12/0.07/0.09/0.06/1.12; palpus brown with white hairs;

proboscis yellow-orange with white hairs.

hypopygium, lateral view, in ethanol; E – apex of hypopygium, lateral view, dry.

Thorax. Dark metallic green with bronze reflections; pleura with white pruinosity;

setae black; 5 strong dorsocentral bristles; 3 long irregularly paired acrostichals;

scutellum with 2 strong and 2 hair-like bristles.

Legs including coxae yellow, but mid coxa and hind knee brown; segments 4

and 5 of fore and hind tarsi brown; hind tarsus blackish brown from tip of basitarsus;

fore and mid coxae with white hairs and 2–3 white subapical bristles; hind coxa with 1 yellow bristle at base; fore and mid femora with ventral rows of white hairs,

not longer than diameter of femora; tibiae and tarsi simple, without strong setae or remarkable hairs; tibia and tarsomere (from first to fifth) length ratio (mm): fore leg: 1.81/1.25/0.55/0.34/0.23/0.18, mid leg: 2.41/1.75/0.7/0.48/0.26/0.16, hind leg:

3.14/1.1/1.02/0.59/0.29/0.23.

Wing ( Fig. 1C ). Widest at middle, smoky anteriorly, veins yellow-brown; costa with simple setulae; R 1 long; R 4+5 gently curved to M in apical third; M 2 absent without fold or indication on membrane; M strongly bent, with nearly right-angle curve; ratio of parts of costa between R 2+3 and R 4+5 to those between R 4+5 and M 1,

1.08/0.22; crossvein dm-m almost straight; ratio of crossvein dm-m to apical part of

M 1+2 (fork-handle) to apical part of M 4, 0.8/1.17/0.88; anal vein fold-like; anal lobe well developed and alula small; anal angle acute; lower calypter yellow with brown rim and golden cilia; halter light yellow.

Abdomen. Terga metallic blue-brown, with bronze reflections and matt brown areas with metallic reflections at tergal overlap between segments 2–6; tergum 1

with white hairs and black marginal setae; segment 5 swollen, with numerous long ventral bristles; segments 6, 7 and hypopygium dark brown ( Fig. 1D–E ); phallus and hypandrium elongate and narrow, with phallus extending only slightly beyond the hypandrial apex; epandrial lobe elongate-ovate, with setae at base, at 3/4 and at apex; surstylus with 3 arms and short setae; cercus strongly curved, with strong and long dorsolateral setae, and apically hooked and narrow, bearing inner lobe, 2–3

simple and 1 clavate apical seta.

MEASUREMENTS (mm). Body length 7.3; antenna length 1.4; wing length 6.5;

wing width 2.4.

FEMALE. Unknown.

DIAGNOSIS. Mesorhaga tanzaniensis sp. n. differs from all other Afrotropical species of the genus in yellow antenna; almost entirely yellow legs; brown spots on abdominal tergites. The antenna and abdomen are entirely brown to black, usually partly dark femora in other species. Male cercus of the new species is species-

specific, with very long dorsolateral setae, longer than cercus. It is the largest

Afrotropical Mesorhaga species.

ETYMOLOGY. The Latin name of the species belongs to the country of origin.

Figures

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