Ferdinandea volkovae, Barkalov, 2022

Barkalov, A. V., 2022, Description of a new hoverfly species of the genus Ferdinandea and the female of Eumerus muratovi from Tajikistan (Diptera: Syrphidae: Eristalinae), Zoosystematica Rossica (Zoosyst. Rossica) 31 (1), pp. 66-73 : 67-71

Ferdinandea volkovae sp. nov.

( Figs 1A–E , 2A, B )

Holotype. Male, Tajikistan, “GBAO [Gorno-Badakhshan Autonomous Prov.], Bodom-Dara ushch. [Gorge], 37°10′N 71°53′E, 2870 m, 29.VII.2021, A. Barkalov leg.” [in Russian].

Description. Male. Body length 11.8 mm; wing length 10.5 mm.

Head. Face broad, distinctly broadened ventrally, with distinct broad tubercle, dark brown in dorsal and lateral parts and broadly yellow medially ( Figs 1A , 2B ). Paraface moderately broad yellow in dorsal two-thirds and brown in ventral one-third, covered with silver pollen and short fine pile. Gena broad yellow, with white pollen and long yellow pile. Frons broad, black, with dense white pollen and comparatively short fine black pile; frontal angle slightly more than 90°. Antenna with scape and pedicel black, basoflagellomere enlarged, rounded, mostly brown, with a large orange spot posteroventrally ( Fig. 1B ), arista long, gradually tapering, brown, without pile. Eyes connected for distance approximately equal to length of ocellar triangle, densely covered with white pile. Vertex with dense grey pollen and long black pile; ocellar triangle isosceles: distance between anterior and posterior ocelli distinctly longer than distance between posterior ocelli.

Thorax. Postpronotum yellowish, with dense grey pollen. Scutum with dense grey pollen and mixed short white and long black pile, on sides with strong black bristles. Scutellum mostly yellow, darkened in anterior half, with eight strong long black bristles on posterior margin ( Fig.2A ). Pleura black, with dense grey pollen and yellow pile, with some black pile on posterior anepisternum. Posterodorsal corner of posterior anepisternum with three strong, long black bristles. Legs: coxae black, with dense grey pollen and yellow pile; femora black in basal half and yellow in apical half, covered with black and yellow pile; fore and mid tibiae yellow with narrow black ring in apical half; hind tibia completely yellow; tarsi yellow. Wings finely infuscate brown with veins black in apical half and yellow in basal half, without black macula. Squama yellow with yellow cilia. Halteres yellow with brown head.

Abdomen black with metallic luster. Terga I–II covered with grey pollen; tergum II with large shiny yellow maculae laterally; terga III–IV completely shiny, covered with dense yellow erect and semierect pile. Sterna black with narrow yellow vittae, with grey pollen along hind margin; sterna I–II with long yellow erect pile; sterna III–IV with yellow pile laterally and short black adjacent pile medially.

Genitalia as in Fig. 1C–E . Surstylus in lateral view uniformly thickened. Upper lobe of hypandrium with elongate left plate. Apical sclerite of aedeagus with a hump dorsally.

Female unknown.

Comparison. Ferdinandea volkovae sp. nov. differs from all valid Palaearctic species of the genus in the following characters: face dark brown in upper part, frons and mesonotum completely covered with grey pollen, scape and pedicel black, and in the details of the male genitalia (most important diagnostic details of the genitalia indicated by arrows in Fig. 1C–E ).

In the key to European species of the genus Ferdinandea ( Speight & Sarthou, 2011) the new species keys out to F. aurea Rondani, 1844 , but differs from it in the rounded postpedicel and black basal half of femora and middle part of tibiae (in F. aurea , postpedicel is deeper than long and all femora and tibiae are entirely yellow).

Distribution. Ferdinandea volkovae sp. nov. is known only from the type locality ( Fig. 4 ), situated in the Roshtkala District of the Gorno-Badakhshan Autonomous Province of Tajikistan.

Note. The holotype was collected on a poplar trunk ( Populus sp. ) in the floodplain thickets of sea buckthorn ( Hippophae rhamnoides ) and willow ( Salix sp. ). These thickets are located on the path for driving flocks of sheep and goats, so that the area around them is an anthropogenic desert.

Etymology. The new species is named in the honour of Tatyana Volkova, who helped to organise the expedition of 2021.

Figures

Fig. 1. Ferdinandea volkovae sp.nov., male (holotype). A, head, in lateral view; B, antenna, in lateral view; C, surstylus and cercus, in lateral view; D, superior lobe of hypandrium, in lateral view; E, aedeagus with apodeme. Arrows indicate diagnostic characters. Scale bars: 0.45 mm (A, B), 0.23 mm (C–E).

Fig. 2. Ferdinandea volkovae sp. nov., male (holotype). A, general appearance, in lateral view; B, head, in anterior view. Scale bars: 5 mm (A), 1 mm (B).

Fig. 4. Collecting localities in Tajikistan. 1, Ferdinandea volkovae sp. nov. (holotype); 2, 3, Eumerus muratovi Barkalov, 2020 (females).