Corononcodes coronatus Speiser, 1920

Barraclough, D. A., 2001, A review of the South African species of Corononcodes Speiser (Diptera: Acroceridae), African Invertebrates 42, pp. 95-104 : 97-99

Corononcodes coronatus Speiser, 1920

Corononcodes coronatus Speiser, 1920 ; Schlinger, 1980: 377; Barraclough, 1984: 52.

Holotype female: SOUTH AFRICA: Northern Cape: ‘Kimberley [28º45'S: 24º46'E] / Capland / Dr. Brauns. / 6. 09’ [date written vertically on righthand side of label]; Corononco - / des / coronatus / Speiser / Type’ [black ink on red card]; ‘ Corononcodes / coronatus / P. Speiser det. / Type’; ‘ Corononcodes / coronatus Speis / Type 57’. [red ink on white card]. In NMSA; in poor condition, entire body glued to card, abdomen detached and glued down with ventral-side up, right hind leg missing and left wing badly torn.

Redescription: Based on female holotype.

Female:

Measurements (in mm): Total length, excluding antennae [ca. 10.8]; wing, from extreme base [7.9].

Head: Eyes and occiput blackish; occiput not visible in dorsal view. Eye with pile restricted to a vertical band of hairs at dorsomedial extremity, length of band about 3–4 times width of scape apex; pile on eye and occiput white. Ocellar tubercle height half to three-fifths head-height; pile elongate, white; ocelli barely visible although apparently 2 present (median ocellus possibly concealed beneath debris), colour brown; ocellar tubercle variously rugose, middle section prominently raised and U-shaped posteriorly where it is markedly higher than anterior margin of this section, height of middle section reaching almost three-fifths total height of tubercle, lower lateral and posterior section with paired and posteriorly directed posterior projections barely evident in dorsal view. Scape and pedicel dark brown; scape bare dorsally; pedicel about half length of scape, with short dorsal hairs; pile on pedicel much less than half length of that on eye, occiput and ocellar tubercle. Flagellum sharply pointed apically; entirely dark brown; length about 0.8–0.9 times height of eye. Epistomal region relatively well developed and protruding anteriorly. Gena well developed in profile, depth subequal to length of scape. Proboscidial covering and buccal cavity apparently brown.

Thorax: Entirely dark brown to black, pleura slightly paler. Pile white; absent below anepisternum, anepimeron and katatergite, also absent from upper anterior margin of anepisternum, extreme lateral corners of scutellum and from lower half of proepisternum; pile length almost reaching 2.0 times as long as on head. Pro- and metathoracic spiracles yellow. Halteres detached.

Legs: Coxae mainly medium to dark brown (paler brown on posterior surfaces), pile white and slightly shorter than head pile, pile sparse on posterior surfaces of fore and mid coxae and largely absent on posterior surface of hind coxa. Trochanters brown to yellow-brown, pile white and shorter than coxal pile, present on anterior and posterior surfaces of all trochanters. Femora mainly yellow-brown, pile white, at most half as long as head pile, sparse to absent on posterior surfaces. Tibiae yellow-brown, pile white, shorter and sparser than femoral pile; spurs well developed, comprising talon-like projection, hind spur 1.5 times length of scape. Tarsi yellow to brown, pile shorter than tibial pile, but slightly longer dorsally at apex of each segment, pile not markedly elongate dorsally at apex of fifth segment. Claws dark brown to black; pulvilli yellow to yellow-brown.

Wing: Membrane hyaline. Veins yellow to pale brown, but costa and subcosta darker brown. Vein M 3 complete, originating from basal crossvein. Vein R 4+5 reaching wing margin. Upper calypter entirely white pruinose. Lower calypter entirely white pruinose; pile completely absent.

Abdomen: Widest at TII. Mainly dark brown (although dorsum much fragmented). Pile white, apparently short, but much abraded.

Male: Unknown.

Discussion: This species is known only from the badly damaged female holotype. It is the largest South African species in the genus, and has the most prominently developed ocellar tubercle (see Barraclough 1984: Figs 23 & 24). The holotype (collected by Dr Brauns) was original deposited in the Transvaal Museum, but was transferred in 1983, together with most of the Transvaal Museum’s Diptera collection, to the Natal Museum. In his original description, Speiser erroneously stated that the holotype was a male; this error was pointed out by Schlinger (1960: 466). Speiser also erroneously stated that the eyes were bare, whereas eye pile is certainly present, albeit restricted to a vertical band of hairs at the dorsomedial extremity of the eye.