Eumerus bilobatus Barkalov, Mutin, Daminova et Rakhimov, 2020

Barkalov, A. V., Mutin, V. A., Daminova, D. B. & Rakhimov, M. R., 2020, New species of the genus Eumerus Meigen, 1822 (Diptera, Syrphidae) from Central Asia, Far Eastern Entomologist 417, pp. 1-7 : 3-6

Eumerus bilobatus Barkalov, Mutin, Daminova et Rakhimov , sp. n.

http://zoobank.org/NomenclaturalActs/ 0F82D42F-C5B4-4932-9B6D-A3BD92433BFC

Figs 1–12

TYPE MATERIAL. Holotype – ♂, Turkmenistan: vicinity of Ashgabat City ,

Firuza settlement, 23.IV 1987, A. Barkalov leg. [ SZMN]. Paratypes (20 specimens):

Turkmenistan: 15 km west of Firuza settlement, Dushak Mountain, 4–11.V 1987,

6 ♂, 8 ♀, A. Barkalov leg. [ SZMN]; Uzbekistan: Nuratau Nature Reserve , Hayat-

bashi Mountine 40,49895°N, 66,72956°E, 17.VI 1997, 1 ♂, D. Daminova leg.

[ SZMN]; Nuratau Nature Reserve , Hayat Valley 40,518950°N, 66,749560°E , 5.V

1995, 1 ♂, D. Daminova leg. [ DBD]; Nuratau Nature Reserve , Andibarout valley ,

40,52187°N, 66,74111°E, 14–15.VI 1997, 2 ♂, D. Daminova leg. [ DBD]; Nuratau

Nature Reserve , Alichak valley, 40,508612°N, 66,739324°E, 28.VI 1995, 1 ♂ , D.

Daminova leg. [ SSU]; Qarshi, 19.V 2015, 1 ♂ , M. Proshchalykin leg. [ FCBV] ;

Darband, 10.V 2015, 1 ♀, M. Proshchalykin leg. [ FCBV] .

DESCRIPTION. MALE. Body length 6.5–7.3 mm, wing length 5.0–6.5 mm.

Head. Face and frons with dense silver dusting and white hairs. Eyes holoptic,

with very short sparse white hairs; line of their connection a little bit shorter than the length of frons ( Fig. 5 ). Vertex shiny black, with white or yellow hairs, with spots of grey dusting on hind margin near eyes; ocellar triangle isosceles, with white hairs. Occiput broad, shiny, with white hairs. Antennae: scapus and pedicel black,

latter with narrow yellow rim, short black dorsal hairs and long white ventral ones;

postpedicel oval ( Fig. 7 ) and entirely black or irregular form with antero-ventral angle ( Fig. 8 ), mainly dark-brown to black except reddish baso-lateral spot, with dense silver dusting.

Thorax. Postpronotum shiny black with white hairs. Scutum shiny black, with two narrow sub-medial stripes of grey dusting on anterior half and dusting spots on sides which don’t reach postalar calli, mainly with short erect white hairs except row of short strong black bristles on lateral margin before postalar callus. Scutellum distinctly margined, shiny black, with white hairs longer on hind margin. Pleura shiny black with fine white dusting and white hairs, postero-dorsal part of katepi-

sternum and katatergum glossy shiny.

Legs. Coxae black with white hairs, fore coxa with reddish tip; femora black with yellow bases and tips; hind femur moderately swollen, without any process or knobs,

with short black bristles ventrally ( Fig. 10 ); tibiae without any process, reddish-

yellow on basal half and apex, and black or brown on apical half; hind tibia with a row of short addressed black bristles on basal third; tarsi simple, not broadened not swollen, yellow ventrally, fore tarsus blackish dorsally, mid tarsus yellow with blackish segments 4–5, hind tarsus mainly reddish-brown except dorsal surface basitarsus and segments 4–5 blackish; segments 1–4 of mid tarsus with short black bristles ventrally. Wings hyaline without dark spots. Squama white, halter yellow.

Abdomen. Parallel-sided, as wide as scutum, black with fine bluish reflection;

tip of tergite IV narrowly yellow-brown; tergites II–IV with oblique grey spots ( Fig.

1-2); sides of tergites I–III and hind half of tergite IV with short white hairs, middle part of all tergites with depressed short black hairs. Sternites black, sternite V with broad shallow notch. Hypopygium – as in Figs 11, 12 .

dorsally; 4 – female laterally. Scale bars 1 mm.

VARIABILITY. The form and coloration of postpedicel vary from oval ( Fig. 7 )

and completely black (in some specimens from Turkmenistan) to irregular with antero-ventral corner ( Fig. 8 ) and big orange-reddish spot in the middle (specimens from Uzbekistan). Sub-medial stripes of grey dusting on scutum can be distinctly seen only in its anterior1/3. Tergite IV of one male from Turkmenistan reddishbrown on sides and black in the middle (a narrow reddish stripe on posterior margin in other specimens).

of female dorsally; 7–8 – male pedicel and postpedicel laterally; 9 – female pedicel and postpedicel laterally; 10 – hind leg of male, anteriorly; 11 – male genitalia laterally; 12 –

surstylus anteriorly; 13 – E. sogdianus Stack., male genitalia laterally. Scale bars in mm.

FEMALE. Body length 7.2–8.5 mm, wing length 6.3–6.6 mm.

Similar to male except the characters of sexual dimorphism ( Figs 3, 4 ).

Postpedicel bigger than that of the male, black outside and with big reddish-brown medial spot inside ( Fig. 9 ). Frons comparatively narrow ( Fig. 6 ) with narrow stripe of grey dusting near eye margin and transverse stripe of grey dusting varying in width. Ocellar triangle equilateral ( Fig. 6 ). Tergite IV black either with very narrow reddish-brown stripe on posterior margin or completely black.

DIAGNOSIS. In key to Palaearctic species of the genus Eumerus (Stackelberg,

1961) males of new species with blackish postpedicel goes to Eumerus sogdianus

Stackelberg, 1952 but distinctly differ from latter by bifurcated surstylus ( Figs 11,

12 vs. Fig. 13 ). In the same key specimens with big orange-reddish spot on postpedicel goes to E. acuticornis Sack, 1933, but differs from it by blackish dorsally fore tarsi and by partly blackish postpedicel (in E. acuticornis yellow fore tarsi and light red postpedicel).

In the key to European species of the bactrianus species subgroup (Grković et al., 2019) E. bilobatus sp. n. goes to E. bifurcatus van Steenis et Hauser, 2019. The new species well differs from E. bifurcatus by yellow hairs on ocellar triangle, shorter ventral hairs on hind femur, tergite IV with narrow yellow-brown tip and by different structure of the male genitalia (in E. bifurcatus ocellar triangle with black hairs, ventral hairs on hind femur 3-5 times longer than dorsal hairs, and tergite IV completely black).

DISTRIBUTION. Uzbekistan and Turkmenistan.

ETYMOLOGY. The species is named because of the two-lobed form of surstylus.

Figures

Figs 1–4. Eumerus bilobatus sp. n. 1 – male dorsally; 2 – male laterally; 3 – female

Figs 5–13. Eumerus ssp. 5–12 – E. bilobatus sp. n.: 5 – head of male dorsally; 6 – head