Pherbellia shatalkini Rozkošný, 1991

Kurina, Olavi & Knutson, Lloyd, 2019, First record of Pherbellia shatalkini Rozkošný (Diptera: Sciomyzidae) from Mongolia, with a redescription of the male genitalia, Zootaxa 4567 (3), pp. 587-592 : 588-590

Pherbellia shatalkini Rozkošný, 1991 ( Fig. 1 )

Material studied. Paratypes. 1 ♂, RUSSIA, Amur area, Zeya , 21.vi.1978, A. Shatalkin leg. (on pin, genitalia in glycerol in microvial on same pin, ZMUM) ; 1 ♀, same data except 7.vii.1981 (on pin, ZMUM) . New material . 1 ♂, MONGOLIA, Govi-Altai Aimag, Khasagt-Khairkhan mountain range, 15 km south of Jargalan , E.P. Nartshuk leg., 14- viii-1970. [Original label in Cyrillic alphabet: MOHГOЛИЯ, Г.-Aлт. Aйм.,/ xp. Хacaгт-Хaйpxaн/ 15 км Ю Джapгaлaнa/ Нapчyк 14.VIII. 970] (on pin, genitalia in glycerol in microvial on same pin, ZIL) ; 1 ♂, MONGOLIA, Uvs Aimag, Khovd Sum: braid of Shiver Gol (river), 12 km E Khovd, N 49.24592° E091.06491°, elev. 1489 m; 6-vii-2010; J. Gelhaus 1304. Mongol Ag. Insect Survey, MAIS 10070604 (on pin, genitalia in glycerol in microvial on same pin, ANSP) .

Redescription of male genitalia ( Figs. 2 A–E, 3 A–E). Epandrium in lateral view almost square, lateroventral margin essentially straight. Hypandrium very broadly rounded medially with apico-medial apron, posteriorly with large, concave, plate-like extensions enclosing apex of aedeagal apodeme and internal genitalia. Anterior surstylus with broad, triangular, plate-like connection articulated with ventral margin of epandrium; in postero-ventral view appearing bilobed. Anterior lobe (in anterior or posterior view) oblong, concave on posterior surface, apically rounded, in lateral view elongate, distal 1/3 not pigmented, with minute, closely appressed, apico-ventral plate, which is curved posteriad and invested with minute, hair-like setulae; most notably, and unlike anterior lobe of any other species of Pherbellia , in anterior view anterior lobe bearing strongly sclerotized, square projection at about midlength on distal surface, apically with 5 or 6 strong setae equal in length to that of square projection (depending upon angle of view, marginal setae might appear to be on postero-apical corner of anterior lobe); unpigmented flange on posterior margin of anterior lobe bearing a few widely spaced setulae; posterior lobe in anterior view appearing spatula-like, in lateral view appearing elongateacute; anterior and posterior lobes separated by deep sinus. Posterior surstylus invested with long, sparse setae; surstylus broadly expanded basally, ventrolateral to cerci, with acute, posteriorly directed, evenly curved hook on median anterobasal corner; surstylus in posterior view with broad constriction beyond basal 1/3, then expanded mesially and gradually constricting to narrowed, bluntly pointed, slightly recurved apex. Cerci elongate, densely setulose, with single apical seta longest. Internal genitalia: hypoproct fusiform; pregonite (gonopod) a simple, slightly curved and apically expanded rod with well distinguished, toothlike warts on apical half; postgonite (paramere) a large Г-shaped process, with apical, laterally directed arms acute apically, each bearing a diaphanous, caplike, concave plate and with a few setulae basally. Aedeagal apodeme large, straight, apical 1/4 at 45° angle, expanded; ejaculatory apodeme 2/3 length of aedeagal apodeme, apical plate very broad, lightly pigmented.

Taxonomy position. With a short midfrontal stripe not extending beyond the middle of the frons and an unpatterned wing, P. shatalkini keys to the subgenus Chetocera Robineau-Desvoidy (including 22 species in the Palaearctic) according to Rozkošný’s (1964) Pherbellia delineation in seven subgenera. Following Steyskal’s delineation of species groups of Pherbellia ( Steyskal 1949, 1961, 1963, 1966), P. shatalkini is in the group of species with a short midfrontal stripe, two fronto-orbital setae, and a “hairy” anepisternum. Rozkošný (1991) did not name them as a group, but in his key to species with that combination of characters [except for a long midfrontal stripe in P. mikiana (Hendel) ], the species P. mikiana , P. czernyi (Hendel) , P. pilosa (Hendel) , and P. shatalkini appear together. Among these species, P. mikiana (Mediterranean and coastal western Palaearctic) is distinct from P. shatalkini in having the midfrontal stripe reaching the anterior margin of the frons, vein M 1+2 with a stump vein, infuscated crossveins, a completely black basal flagellomere, and in major male postabdominal characters, especially peglike setae on the anterior surstylus. As in P. shatalkini , P. czernyi (Central European) has a short midfrontal stripe and lacks a stump vein on vein M 1+2, but the anepisternum has only 10–12 hair-like setulae (many minute setulae on posterior half in P. shatalkini ), all basitarsi are contrasting white (brown in P. shatalkini ), both surstyli are elongate and rather simple (anterior surstylus consists of two lobes in P. shatalkini ), and the hind femora are densely haired ventrally (with three strong setae anterodorsally deviating from other setosity in P. shatalkini ). Pherbellia pilosa (South Mediterranean Europe, Near East, Central Asia) has the fore basitarsus slightly paler than the rest of the tarsus (entirely brown in P. shatalkini ), fore coxa with many setae above the middle (with only two setae in P. shatalkini ), and anterior part of anterior surstylus clublike, very densely setose across the apex (with strongly sclerotized square projection in P. shatalkini ). Pherbellia shatalkini is more similar to P. frohnei Steyskal (Naknek, Alaska, U.S.A.) but differs especially in features of the male postabdomen. In P. frohnei the anterior lobe of the anterior surstylus has a group of six or seven setae on the postero-mesial corner, not on a spatulate, sclerotized process, and about six strong marginal setae arising at midlength on the anterior surface of the anterior lobe as in P. shatalkini . In P. frohnei , the anterior lobe has a short anteroventral process, according to the figure by Steyskal (1963: fig. 1), as in P. shatalkini (not figured by Rozkošný 1991: figs 13, 14). In lateral view, the posterior surstylus in P. shatalkini is strongly indented beyond the basal 1/3 (figured as straight by Rozkošný 1991: fig. 19) but is only slightly indented in P. frohnei . The internal genitalia have not yet been described nor figured for P. frohnei .

Figures

FIGURE 1. Pherbellia shatalkini (lateral view, postabdomen detached), specimen from Govi-Altai Aimag, with original label of collecting data.

FIGURE 2. Pherbellia shatalkini, male genitalia. A, C, D—posterior view; B—lateral view; E—posterolateral view. Abbreviations: aa—aedeagal apodeme, al a ss—anterior lobe of anterior surstylus, ce—cercus, ep—epandrium, hy—hypandrium, pl a ss—posterior lobe of anterior surstylus, p ss—posterior surstylus, sp—setose process on anterior lobe of anterior surstylus.