Episyrpbus petilis, Vockeroth J.R., 1973

Vockeroth J. R., 1973, Some New or uncommon Syrphini (Diptera: Syrphidae) from Southern Africa, Annals Natal Mus. 21.3.595 - 607. pdf 21 (3), pp. 595-607 : 602-604

Episyrpbus petilis n. sp.

Very slender species with abdomen almost parallel-sided, the tergites mostly yellow and usually with narrow apical or subapical black bands. Length 8,1 to 10,4 mm.

Male. Face parallel-sided, narrow, at widest point 0,32 times maximum head width. Face, front and cheek pale yellow, whitish pollinose except for subshining subquadrate supra-antennal area about half as long as front, and subshining facial tubercle. Postcranium blackish above, paler below, with silvery pollen. Head hairs yellow to white. Antenna yellow, arista and upper t of third segment dark brown, third segment 1,3 times as long as broad.

Mesonotum brown, unstriped, lightly yellow-brown pollinose; humerus and broad notopleural area yellowish, densely yellow pollinose; postcallus yellow-brown, moderately yellow pollinose. Mesonotal hairs yellow. Scutellum pale yellow, lightly yellow pollinose. Scutellar hairs long, mostly dark brown to black. Subscutellar fringe long, yellow, rather sparse, in two irregular rows. Metanotum dark brown. Pleura yellow brown, with fine white or yellow pollen; sternopleuron, except semicircular area above upper hair patch, light

brown. Pleural hairs pale yellow. Anterior mesopleuron with erect hairs posterodorsally and on lower half. Anterior end of sternopleuron with two fine hairs; upper and lower sternopleural hair patches joined posteriorly by a single row of hairs. Metasternum with six long pale hairs. Wing pale yellow-brown, very slightly darker towards apex; stigma pale brown. Alula very slightly narrowed; its posterior margin slightly concave. Wing membrane with the following area bare: first costal cell except very narrow margins, anterior i ofbasal t of second costal cell, first radial cell (cell basad of basal cells) except extreme base and posteroapical angle, most of basal half of first basal cell in front of spurious vein and small area at base of cell behind spurious vein, basal t of second basal cell except narrow anterior margin beyond mid length of cell and narrow posterior margin beyond t length of cell, anterior margin of about basal half of anal cell, an elongate narrow area in front of auxiliary vein and a shorter narrow area behind auxillary vein. Squama pale yellow, the margin of the upper one brownish; fringe yellow. Haltere with yellow stalk and brown knob. Legs mostly yellowish-white to yellow-brown, the fore and mid coxae, tibiae and tarsi very pale, the hind femur and tibia darker, last four segments of hind tarsus brown. Hairs of legs mostly pale yellow; those of posterior surface of mid femur, and of hind leg, yellow-brown to brown.

Abdomen (fig. 4a) slender, elongate, nearly paraIlel-sided. Tergites mostly dull yellow, 1 to 3 subshining, 4 and 5 more pollinose, with black markings as follows: median i of tergite I; basal triangle and narrow apical band on tergite 2, the triangle basally about! as wide as tergite, the band very slightly narrowed laterally; apical band on tergite 3, the band not narrowed laterally; a narrow preapical band on tergite 4, the band apparently not reaching margins oftergite. Tergite 5 apparently slightly darkened apically. Sternites yellow, 4 and 5 discoloured but apparently without distinct markings. Postabdominal sclerites mostly yellow; sternite 8 dark brown, shining. Hairs of segment I and those near base of segment 2 yellow, other abdominal hairs brown. Hairs of tergite I and lateral hairs of tergite 2 very long, the longest hairs of tergite 2 more than! as long as width of tergite. Terminalia (fig. 4b,c): Surstylus broad, with broadest surface directed laterad, tapering on gentle curved posterodorsal margin to a subacute apex. Sternite 9 with posteroventral emargination about 0,6 times as long as sternite, the ventromedian margin of apicolateral process not turned outward as a thin flange. Superior lobe with apical tooth dark, situated at posterodorsal angle of lobe.

Female. Very similar to male, differing as follows: Front black except for yellow subquadrate area above antenna, upper half finely blue-grey pollinose with or without an indistinct shining median stripe, the pollen continuing ventrad along eye margins on to face. Width offront at narrowest point (at level of anterior ocellus) 0, \ 0 times maximum width of head. Disc of mesonotum dark brown to black, sometimes with very faint submedian presutural stripes of greyish pollen. Hairs of mesonotum and scutellum slightly shorter. Pleura varying in colour from entirely pale yellow to yellow-brown with about lower! dark brown. Sternopleuron with two or three anterior hairs; row of hairs joining hair patches sometimes incomplete. Fore femur and mid tarsus with dorsal hairs mostly brown. Tergites pale yellow to reddish-yellow; basal black triangle of tergite 2 sometimes extending caudad to apical band; dark bands of tergites 3 and 4 sometimes very indistinct or apparently absent. Hairs of tergite 1 and lateral hairs of tergite 2 slightly shorter.

Types: Holotype 0', MO<; AMBIQUE, Tumbine Mountain, Milange , vii. 1957 (B. & P. Stuckenberg) ; in Natal Museum ( No . 1585). Paratypes: 汾 Ⱐ same data as holotype; 䥾Ⱐ Goronzoga Mountain, Manica-Sofala Dist., 䵯繡浢楱略Ⱐ 1 200 m, ix. 1957, in mountain forest (B. Stuckenberg); I ~ , N. Vumba , Rhodesia, 27.iii. l965 (D. Cookson) ; ㉾ Ⱐ Laurenceville, Vumba , Rhodesia, I and 27. iii.1963 (D. M. Cookson) ; 1 ~ , Karkloof , Natal, 17. iv.1955 (B. Stuckenberg); 1 ~ , Hogsback, north of Alice, E. Cape Province, (B. & P. Stuckenberg) ; in Natal Mus ., Can. Nat. ColI