Eumerus similis Gilasian & van Steenis, 2022

Gilasian, Ebrahim, van Steenis, Jeroen & Parchami-Araghi, Mehrdad, 2022, Six new species of the genus Eumerus Meigen, 1822 from Iran (Diptera, Syrphidae), Journal of Insect Biodiversity and Systematics 8 (3), pp. 483-512 : 496-499

Eumerus similis Gilasian & van Steenis sp. nov. ( Figs 10, 11, 12B, D)

https://zoobank.org/ urn:lsid:zoobank.org:act:08CC26BD-6EDD-4FA2-AA3A-47125A0D0690

Differential diagnosis. Although it has morphological similarities to E. obliquus (Fabricius, 1805) , strikingly differs from this species in male genitalia for its hook-shaped and apically rounded posterior lobe of surstylus ( Fig. 12B) compared to that rectangularly shaped in E. obliquus (See Fig. 127A in Grković, 2018, page 172 for the male genitalia of E. obliquus ).

This species is incorporated into the identification key to the species of the E. obliquus species group provided by Ricarte et al. (2020) as follows:

5. Metabasitarsus in male laterally compressed, with a dorsal ridge. ............................................................... 5 (a) — Metabasitarsus without a dorsal ridge. ..................................................................................... E. punctifrons

5 (a) Vertex with black pile and extensive areas free of pollinosity or sparsely pollinose; posterior lobe of surstylus recangularly shaped apically. .................................................................................................... E. obliquus

— Vertex without black pile, covered in dense pollinosity except for a narrow area surrounding each ocellus; posterior lobe of surstylus hook-shaped and apically rounded. ...................... E. similis sp. nov.

Etymolog y. The specific epithet “similis ” is Latin for ‘resembling’ based on the similarity in non-genital characters of this species with E. obliquus . It is to be treated as a noun in apposition.

Material examined. Holotype: IRAN ♂ (pinned), Khuzestan prov., Shoush, Karkheh National Park, Persian Fallow Deer Sanctuary , 32°06′25.5″N 48°26′14.8″E, 11 March–10 May 2015, 53 m, Malaise trap, E. Gilasian ( HMIM) . Paratypes, 2 ♀♀: 2 ♀♀, (one pinned, one glued to a card point), same data as holotype ( HMIM, JSA) .

Description Male. Body length: 6.3 mm; wing length: 5.2 mm. Head ( Figs 10C, D). Eyes short pilose, holoptic; eye contiguity 0.65 times as long as frontal triangle; face white pilose, densely covered with white pollinosity; frontal and vertical triangles almost equal in length, with white pollinose and white pile; head in frontal view about 3 times as wide as face; ocellar triangle isosceles, white pollinose except for circle shiny area around ocelli; distance between posterior ocelli and posterior margin of eye about 0.6 times as long as ocellar triangle; occiput grey pollinose; frontal triangle about twice as wide as ocellar triangle; vertex at posterior corner of eyes about 1.1 times as wide as vertex over posterior ocelli; head in dorsal view 5.6 times as wide as vertex at posterior corner of eyes; antenna brownish-black, arista 1.65 times as long as basoflagellomere ( Fig. 10E). Thorax. Scutum with long white pile, predominantly white pollinose except for two median blackish vittae and four semi-square blackish maculae (two anteriorly and two posteriorly located to transverse suture) ( Fig. 10A); scutellum blackish, with long white pile, densely white pollinose at posterior margin; pleurae blackish, covered with whitish pile except for bare meron and katepimeron; metasternum pilose. Legs. Yellowish-white pilose; femora predominantly brownish-black except for apical narrow orange margin; protibia and mesotibia orange in basal 1/3 and blackish in apical 2/3; metatibia orange in basal 1/4 and blackish in apical 3/4; tarsi orange ventrally and brownish dorsally, metabasitarsus blackish dorsally; metafemur strongly incrassate, about 2.6 times as long as wide ( Fig. 10F), ventral pile relatively long, about 1/2 times as wide as metafemur; anteroventral and posteroventral margins of metafemur with an apical row of 8 and 6 black setae respectively; metabasitarsus widened, laterally compressed in dorsal portion, with a longitudinal row of black pile dorsally. Wing. Hyaline; entirely microtrichose; calypters yellowish-white; halter yellowish-orange. Abdomen ( Fig. 10G). Brownish-black with short whitish pile; terga II–IV each with a pair of oblique pollinose fascia; lateral and posterior margins of tergum IV white pollinose; sternum IV rectangular, with a narrow median V- shaped incision posteriorly ( Fig. 10H). Male genitalia. Hypandrium simple; epandrium, cercus, posterior and anterior lobes of surstylus as in Figs 12B, D.

Female ( Fig. 11). Body length: 6.5 mm; wing length: 5.5 mm. Similar to the male except for the sexual dimorphism and for the following characters: Head in dorsal view 4.4 times as wide as vertex at posterior corner of eyes ( Fig. 11C); metabasitarsus normal, laterally uncompressed.

Distribution. IRAN.

Remarks. The type material of Eumerus obliquus was not available for this study. The original description ( Smit et al., 2017) and the papers on Eumerus ( Grković, 2018) and the E. obliquus group ( Ricarte et al., 2020) were used to identify this species.