Paragus auritus, Stuckenberg, 1954

Stuckenberg, B. R., 1954, The Paragus Serratus Complex, With Descriptions Of New Species (Diptera: Syrphidae), Trans. R. Ent. Soc. Lond 105 (17), pp. 393-422 : 418-420

Paragus auritus sp. n.

This is a large species with elongated antennae. The abdomen is unusually broad in relation to the thorax, the females especially with greatly distended abdomens. There is no median, ventral projection on the penis-sheath, and the inferior claspers are produced into large ventral lobes. The superior claspers are borne on long, narrow processes.

Male.-Head: Face yellow, with small punctures and a short, moderately thick facial pile. Oral tubercle piceous and surrounded by a strip of light brown. Third segment of one antenna missing. Segments of other antenna very elongated, especially the third, and antenna as a whole longer than distance between base of antennae and upper margin of oral tubercle; third segment tapering and cylindrical. Basal segments reddish-brown, the second darker than the first; apical segment dark crineous above, somewhat orange below. Vertex black with strong violaceous reflections. Stripes of hair on eyes distinct, the outermost on each eye being the broadest. Thorax: Mesonotum black with pale blue and violet reflections above, and quite strong blue reflections on the sides, heavily punctate, the punctures rather small. Mesonotal pile quite short and thick, fine, erect and yellow. One of the mesonotal stripes has been obliterated by the pin on which the specimen is mounted, the other stripe distinct and quite heavy, yellow in front and silverygrey behind. Scutellum fusco-piceous on basal half and slightly creamy-yellow on apical half: between these two areaa a narrow intermediate band of 'brown. Sixteen scutellar teeth, each tipped with orange, the middle six teeth only half the length of those on the outside. Legs: Posterior femora brown on middle half, pale teshceous on basal quarter, and yellow on apical quarter. Posterior tibiae pale yellow, almost white on basal half, the remainder yellowish testaceous. Hind tarsi brown with a slight admixture of yellow. The two anterior pairs of femora pale testaceous, except for their distal fifth, which is yellow. The middle and anterior pairs of tibiae pale yellow on their basal two-thirds, very pale testaceous on remainder. The two anterior pairs of tarsi brown with a strong admixture of yellow, almost orange. Wings: Membrane hyaline and moderately glossy, slightly suffused on basal half. Stigma yellow and veim ligneous brown and moderately heavy. Subcosta and apical part of first longitudinal vcin light brown. Abdomen: Conspicuously large in relation to thorax. Slightly carinate, rather rounded and deep, a little flattened on each side of median line, and with prominent shoulders; translucent brown. Corners of first segment and shoulders of second suffused with dark brown, also fourth segment behind median vittae. A he sculpturation present on fourth segment and that part of third segment behind anterior vittae. Remainder of abdomen covered with punctures. Middle three segments with a conspicuous covering of quite long, stout reclinate black hairs which are distinct against pale coloration of abdcmen. White hairs present on fifth segment and also a few on fourth. Anterior vittae rather indistinct, and lying in shallow troughs; middle and posterior vittae distinct, troughs on fourth segment shallow and narrow. Genitalia ( fig. 30 ): Epandrium trapezoid, with upper and lower sides parallel-not quite twice as long as deep. Ventral posterior corners broadly rounded. Cerci rounded and prominent. Styles shaped somewhat like the blade of a pen-knife, only with a broadened base and with upper and lower margins a little notched. Inferior claspers ear-like and well developed; the upper lobe slight, but the lower lobe very large and produced ventrally. Penis-sheath narrow, and completely lacking any median. ventral projection. Superior claspers borne on long, narrow, curved, ventrally-directed projections of the penis-sheath, these projections very characteristic.

Length 8.2 mm.

Holotype male, CEYLON: Kandy, 29. vi. 1892 (Lt.-Col. Yerbury). In the British Museum (Natural History), B.M. 1892-292 .

Female.-Third segment of antennae conspicuously darker than the two basal segments. Frons black with dull cyanescent reflections. The two tomentose strips broad and with irregular inner margins, each with a thin inward projection at upper end. Vertex fuscopiceous with violaceous reflections. Fifteen scutellar teeth. Wings quite strongly suffused with yellow-brown, more strongly 80 on basal half. Abdomen very broad and greatly enlarged in relation to thorax, very deep and rounded, with prominent shoulders. Sides curve rapidly backwards under the bulge of the abdomen ( fig. 33 ). Fourth and fifth segments piceous except for a narrow strip of brown along anterior margin of each median vitta. Third segment with a fusco-piceous strip on each side of median line. Black hairs which were present on abdbmen of holotype well developed and conspicuous, perhaps a little longer and thinner. Fourth and fXth sternites dark, shining fusco-piceous.

Length 8.2 mm.

Allotype female, CEYLON: Anarudhapura, 10.xi. 1890 (Lt.-Col. Yerbuy). In the British Museum (Natural History), B.M. 1892-192 .

Paratypes: CEYLON: KBnthalia , 31. vii. 1890, 17.x.1890, 2 ♂; Trincomali , 19. ii.1892, 1 ♀; Pankullam, 1. i. 1891, 1 ♀ (Lt.-Col. Yerbury). All B.M. 1892-192 . INDIA: Calcutta , 1-17. xii.1908, 1 ♂, ex coll. Brunetti, B.M. 1927-184 . KENYA: Teita Hills, Lumi River , xii. 1912,l ♂. In the Coryndon Museum, Nairobi.

One male from Kanthalia has a paler abdomen than that of the holotype, especially the first segment, which is amber; the same specimen has the dark band on the posterior femora very much reduced. The male from Calcutta completely lacks the dark band on the posterior femora, which are pale amber. The male from Kenya has ten quite long scutellar teeth, each tipped with brown; the mesonotal pile is longer than in the holotype; the posterior femora are dark brown and the other legs are generally darker.

There are some rather puzzling differences in the genitalia, the typical form being illustrated in fig. 30 and an atypical form, which is commoner, shown in fig. 31 . The typical form is only repeated in one of the males from Kanthalia. It seems that the typical form represents a more weakly sclerotised condition of the hypopygium; this weakness has apparently led to distorticn involving extension of the parts during maceration in hot caustic potash.

The genitalia of the male from Kenya are almost identical with those of the males from Ceylon ( fig. 31 ), but differ in that the apex of each style is broader, and the penis-sheath is not strongly angled below. The presence of this species in Africa is unexpected, and the unique specimen may represent a distinct subspecies which would be identified by the differences mentioned above. Unfortunately the specimen is in poor condition.

Shortest paratype 7.3 mm., longest paratype 9.0 mm.

Remarks.-M the specimens that I have of this species are strikingly large. It may be distinguished from the other species in the complex by the elongated antennae.

Figures

FIGS.30-33.-Paragus auritus sp. n. (30) Hypopygium of holotype. (31) Hypopygiurn of male from Kanthalia, Ceylon. (32)Abdomen of holotype. (33) Abdomen of allotype.