Eumerus khiabani 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 : 503-506

Eumerus khiabani Gilasian & van Steenis sp. nov. ( Figs 15, 16, 17B, D, F)

https://zoobank.org/ urn:lsid:zoobank.org:act:E13713FD-4168-42E3-966F-0F7D07D95394

Differential diagnosis: This species is closely related to E. lucidus Loew, 1844 . The eye contiguity in male about 1.3 times (in E. lucidus twice) as long as frontal triangle; basoflagelomere more squarish than in E. lucidus ; frons in female almost entirely white pollinose with exception of a narrow anterior shiny black margin along lunule (in E. lucidus almost without pollinosity medially); vertex in female with large posterolateral pollinose maculae almost 3 times as wide as posterior ocellus (in E. lucidus at most twice as wide as posterior ocellus); scutum in female with a weakly seen medial pollinose vitta and two medio-lateral wider vittae (in E. lucidus with only two medio-lateral pollinose vittae); metabasitarsus along anterior margin with a single row of black and yellowish-orange setae (in E. lucidus with only yellowish-orange setae); tergum II with large triangular yellow maculae posteriorly with white pollinosity (triangular maculae in E. lucidus white pollinose, sometimes narrowly yellow along anterior margin); sternum II and anterior half of sternum III white pilose, sternum IV and posterior half of sternum III black pilose (in E. lucidus sterna II and III entirely white pilose and sternum IV predominantly white pilose with black pile on posterior 1/3); male genitalia as in Figs 17B, D, F and differ from E. lucidus (See Fig. 115B in Grković, 2018).

Material examined. Holotype: IRAN ♂ (glued to a card point), Markazi prov., Haftad-Qolleh Protected Area, Chekab valley , 34°07′05.3″N 50°16′25.3″E, 30 May–3 June 2017, 2219 m, Malaise trap, E. Gilasian & M. Parchami-Araghi ( HMIM) . Paratypes, 1 ♂ 4 ♀♀: Same data as holotype , 3 ♀♀ ( HMIM) , 1 ♂ 1 ♀ ( JSA) .

Etymology. This species is dedicated to our deceased Iranian colleague Dr. Nader Golmohammad Zadeh Khiaban for his contribution to the study of the Iranian fauna of the family Syrphidae . The specific epithet is a noun in the genitive case.

Description Male. Body length: 7.2–7.5 mm; wing length: 4.9–6.3 mm. Head ( Figs 15C, D). Eyes bare, holoptic; eye contiguity almost 1.3 times as long as frontal triangle; face white pilose, densely covered with white pollinosity; frontal and vertical triangles white pollinose with white and yellowish-orange pile respectively; frontal triangle almost 1.2 times as long as vertical triangle; head in frontal view about 3.6 times as wide as face; ocellar triangle isosceles, shiny black and brownish pilose; distance between posterior ocelli and posterior margin of eye about 1.7 times as long as ocellar triangle; occiput grey pollinose; frontal triangle about twice as wide as ocellar triangle; vertex with whitish pollinosity laterally extending to about 3/4 distance between posterior ocelli and posterior eye margin; vertex at posterior corner of eyes about 1.25 times as wide as vertex over posterior ocelli; head in dorsal view about 7 times as wide as vertex at posterior corner of eyes; antenna orange, arista brown; basoflagellomere squarish, arista 1.7 times as long as basoflagellomere ( Fig. 15E). Thorax. Scutum and scutellum shiny black; scutum with two narrow median pollinose vittae, short white pilose ( Fig. 15A); scutellum with marginal rim; pleurae shiny black, covered with whitish pile except for bare meron and katepimeron; metasternum pilose. Legs. Short yellowish-white pilose; femora mostly black, profemur and mesofemur orange in apical 1/5–1/4; metafemur orange apically; tibiae predominantly orange, apical half brownish-black dorsally; tarsi orange, metabasitarsus brownish dorsally; metafemur rather narrow, about 4.5 times as long as wide ( Fig. 15F), ventral pile short and about 1/4 times as wide as metafemur; anteroventral and posteroventral margins of metafemur with an apical row of 8 and 6 black setae respectively; metatibia without dense whitish pile. Wing. Hyaline; entirely microtrichose; calypters yellowish-white; halter yellowish-orange. Abdomen ( Fig. 15G). Predominantly brownish-black with short yellowish-white pile; yellowish-orange triangular maculae on tergum II with whitish pollinose posteriorly; tergum III with a pair of orange oblique maculae with white pollinosity; tergum IV with a pair of narrow oblique grey maculae; sterna yellowish-white pilose; sternum IV squarish, with a median wide V- shaped incision posteriorly ( Fig. 15H). Male genitalia. Hypandrium simple; aedeagal apodeme in lateral view as in Fig. 17F; epandrium, cercus, posterior and anterior lobes of surstylus as in Figs 17B, D.

Female ( Fig. 16). Body length: 7.6–7.8 mm; wing length: 5.5–6.4 mm. Similar to the male except for the sexual dimorphism and for the following characters: Frons almost entirely white pollinose with exception of a narrow anterior shiny black margin along lunule ( Fig. 16C); distance between posterior ocelli and posterior margin of eye about 1.5 times as long as ocellar triangle; posterolateral pollinosity on vertex wider than that in male; vertex at posterior corner of eyes about as wide as vertex over posterior ocelli; head in dorsal view 5.9 times as wide as vertex at posterior corner of eyes; scutum with a weakly seen medial pollinose vitta and two medio-lateral wider vittae.

Distribution. Iran.

Remarks. The type material of the similar species as given in the diagnosis was not available for this study. The papers on Eumerus ( Stackelberg, 1961; Claussen & Standfus, 2017; Grković, 2018; van Steenis et al., 2019) and specimens from the collection JSA were used to identify this species.