Curtonotum sternithrix Tsacas, 1974

Kirk-Spriggs, Ashley H., 2011, A revision of Afrotropical Quasimodo flies (Diptera: Schizophora; Curtonotidae). Part III - the Malagasy species of Curtonotum Macquart, with descriptions of six new species, African Invertebrates 52 (2), pp. 391-391 : 435-438

publication ID	https://doi.org/ 10.5733/afin.052.0212
persistent identifier	https://treatment.plazi.org/id/03FDA115-FFFE-B37C-EBC3-99E3FE08FA64
treatment provided by	Felipe
scientific name	Curtonotum sternithrix Tsacas, 1974
status

Treatment

Curtonotum sternithrix Tsacas, 1974 View in CoL

Figs 3 View Figs 1–8 , 16 View Figs 14–26 , 29 View Figs 27–39 , 57, 60, 63 View Figs 55–63 , 86 View Figs 79–91 , 94 View Figs 92–96

Curtonotum sternithrix: Tsacas, 1974: 708 View in CoL ; figs 3a–e (p. 709), fig. 8e (p. 718). Type locality: “ Madagascar

Est, Antanambe”.

Differential diagnosis:Not closely related to any other species occurring on Madagascar. It exhibits a number of distinctive features, including the presence of three, rather than two, strong humeral setae, and is the only Afrotropical species described to date with conspicuous brown rings around the sockets of the thoracic setae. The abdominal sternites and phallus are highly modified and distinctive. Interpretation of its relationship to other species on the continental Afrotropical Region must await the outcome of a detailed phylogenetic analysis.

Redescription:

Male (primarily based on fieldpinned HT and PT).

As redescribed for C. balachowskyi , differing in the following respects: Measurements: Overall length 5.6 mm; length of head and thorax combined 3.8 mm; length of thorax and scutellum combined 3.1 mm; wing length 4.6 mm.

Head ( Figs 3 View Figs 1–8 , 16 View Figs 14–26 ). Eye height/length ratio: 15:9 (HT); frons ( Fig. 16 View Figs 14–26 ), markedly produced ( Fig. 3 View Figs 1–8 ), parallel-sided, frons length/width ratio: 18:21 (HT), ground colour uniform dark brown, faintly paler medially and in region of ventral margin, lacking any trace of vittae, surface with a few minute pale to dark brown setulae; orbital plates and ocellar triangle golden-silver-grey pruinose, orbital plates and ocellar triangle extremely short, the former extending less than half length of frons, lateral margins with moderately wide, sharplycontrasting, silver pruinose fascia (adjacent to eye margin), widest at antennal insertions; anterior orbital seta strong, ca two-third length of ocellar setae; ocellar setae short, only reaching ca ⅔ length of frons; flagellomere 1 brown, silver-grey pruinose, yellow-brown basally, moderately short, ca twice as long as wide, apex squarely rounded, arista with 11 or 12 long dorsal branches and 3 or 4 ventral branches in addition to terminal fork; lunule and face uniform silver pruinose throughout, face with extremely broad silver fascia (adjacent to eye margin), not contrasting markedly with face, facial carina developed as a prominent ridge; 1 pair of moderately weak vibrissae; occiput with strong, black postocular setae; gena wide, eye height/genal height ratio: 1:10 (HT), silver pruinose, abruptly dirty brown beyond basal angle; palpus narrow, yellow-brown, black microtrichose.

Thorax ( Fig. 3 View Figs 1–8 ). All setae on thorax with prominent dark red ring around each socket, markedly so on mesonotum; mesonotum brown, silver-grey pruinose, with two poorly defined narrow chestnutbrown pruinose vittae; anterior dorsocentral seta much shorter and finer (ca. half length of medial scutellar seta); presutural seta moderately strong, longer and stronger than posterior notopleural seta; postalar setae shorter and finer than acrostichal setae; postpronotum with 3 strong postpronotal setae, the more dorsal longer and reclinate, the medial and ventral shorter and proclinate, with 12–14 finer setulae; anepisternum with more ventral anepisternal setae reclinate, surface with 34 moderately long setulae, those between anepisternal setae longer; ventral katepisternal seta very long and strong, dorsal strong, over half length of ventral, with 22 short, fine setulae at base and along posterior margin.

Scutellum. Golden-brown pruinose, darker than mesonotum, without medial brown pruinose vitta basally, apical margin yellow pruinose; 1 weak basal scutellar setula and 2 weak intermediate scutellar setula, the more medial inserted at 0.8 distance between medial and lateral scutellar setae.

Legs. Fore coxa with 21 brown setulae; femora, tibia and tarsi slightly reddish yellow; tibia darker reddish apically; fore tibia with 4 strong setae on lateral margin, the second basal seta same length as first basal, with ctenidium of 10–13 long, sharp black spinules, separated from each other by two or more basal spinule widths.

Wing (as in Fig. 29 View Figs 27–39 ). Long and narrow, especially cua 1 and m cells, tip evenly-rounded, veins chestnut-brown, membrane deep infuscate brown throughout, darker in r 1 and anterior half of r 2+3 and in region of dm–cu crossvein; dm–cu crossvein subvertical, with slight curvature posteriorly; haltere dirty yellow.

Abdomen. Ground colour of tergites 1–5 reddish yellow to grey pruinose, silver pruinose laterally and at apical margins of tergites; tergite 1 with small, oblique black-brown macula laterally and concolourous medial fascia, these merging slightly at apical margin; tergites 2–5 with extremely broad V-shaped, black median fascia and extensive, concolourous, T-shaped dorsolateral macula, all extensively merging with medial fascia; lateral margin of tergites 2–5 with large, subrectangular, concolourous macula in basal half to ⅔; sternite 4 ( Fig. 86 View Figs 79–91 ), modified, quadrate, evenly rounded apically and laterally, with comb of 16 long, thick, black-brown spinules on apical margin, surface with spare irregular brown setae; sternite 5 ( Fig. 86 View Figs 79–91 ), modified, ovoid, grossly expanded laterally, with raised submedial area in apical ⅔, bearing batch of short regular spines arranged in an arc, each side with comb of eight long, thick, black-brown, apically-directed spines, spinose region with faint brown macula, surface with short setae arranged in irregular rows; sternite 6 ( Fig. 86 View Figs 79–91 ) narrow at base, laterally expanded (may appear narrower than Fig. 86 View Figs 79–91 in undissected specimens), with deep and broad, V-shaped excision apically, with faint brown maculae medially and fascia laterally, merging apically, clothed in very short, irregular black-brown setulae for most of length, those at apical margin slightly longer and more prominent.

Terminalia ( Figs 57, 60, 63 View Figs 55–63 ). Hypandrium ( Fig. 57 View Figs 55–63 , hy) long, with broad-based rounded-angulate dorsobasal lobes; posterior bridge dorsally and ventrally produced (angulate in profile); hypandrial arms broad basally, narrowed apically (viewed laterally), with 2 setulae proximal to postgonite, the more lateral ventrally directed, the medial ventromedially directed (obscured by epandrium on Fig. 57 View Figs 55–63 ), sclerotised area of medial lobes (viewed dorsally), narrow basally and apically, medially expanded and semicircular, here slightly overlapping (not convex); postgonite (obscured by surstylus on Fig. 57 View Figs 55–63 ) long, thin and straight, with slight undulating anterior margin; epandrium ( Fig. 57 View Figs 55–63 , ep) diminutive in proportion to hypandrium, slightly longer than broad (viewed laterally), evenly-rounded on dorsal margin, ventral margin markedly indented, here glabrous, with extensive row of long regular to irregular, apically-directed setae along ventroapical margin; cercus ( Fig. 57 View Figs 55–63 , ce) not prominent, longest setae not exceeding longest setae at ventroapical margin of epandrium; surstylus ( Fig. 57 View Figs 55–63 , ss) very long and narrow, widest basally, slightly curved in apical ⅔; phallus (as in Figs 60 View Figs 55–63 , ph, bp, dp, 63, bp, dp) C-shaped, strongly sclerotised, brown; phallapodeme ( Fig. 60 View Figs 55–63 , ph) fused to basiphallus, basal portion produced and rounded (viewed laterally), with basal margin developed into two extensive, very broad, flat projections in basal ⅔, bifurcated, broad and dovetailed at point of connection with hypandrium; ejaculatory apodeme ( Fig. 60 View Figs 55–63 , ea) free, duct inserted at junction of phallapodeme and basiphallus; basiphallus ( Fig. 60 View Figs 55–63 , bp) wide in basal half, expanded at junction of basiphallus and distiphallus, here with extensive mat of long, translucent, fingerlike, overlapping spinules that continue on basoventral surface of distiphallus; apical section ( Fig. 63 View Figs 55–63 , bp) broad, right lateral margin divided, forming even projection apically; distiphallus ( Figs 60, 63 View Figs 55–63 , dp) extremely long and broad, with extensive membranous area, left lateral margin with membranous fold, clothed in short wart-like spinules, sclerotised area subdivided basally and medially with extensive membranous window, and conspicuous tuft of hairs submedially (viewed laterally).

Variation: Insufficient material is available to assess variability.

Holotype (examined): ♂ MADAGASCAR: “ Madagascar Est / Antanambe 8m / 1.IV.[19]58 / B. Stuckenberg // HOLOTYPE [red card] // CURTONOTUM / sternithrix / Holotype ♂ n.sp. / L. TSACAS DET. 1973 [printed & handwritten] // MUSÉUM PARIS // Curtonotum / sternithrix ♂ / Tsacas, 1974 / A.H. KirkSpriggs vidit 2008” ( MNHN). In excellent condition, left wing detached and glued to mount; re-staged on nu-poly mount; not dissected.

Paratypes (all labelled: “ Curtonotum / sternithrix ♂ [or ♀] / Tsacas, 1974 / A.H. KirkSpriggs vidit 2008”): MADAGASCAR: 1♀ “ Manambato / (Anove) // INSTITUT / SCIENTIFIQUE / MADAGASCAR [pale grey card] // COM. INST. ENT. / COLL. NO14644 // ALLOTYPE [red card] // CURTONOTUM / sternithrix / Allotype ♀ n.sp. / L. TSACAS DET. 1973 [printed & handwritten] // MUSÉUM PARIS” [left wing detached and glued to card] ( MNHN). 1♂ “Manambato / (Anove) // INSTITUT / SCIENTIFIQUE / MADAGASCAR [pale grey card] // PARATYPE [red card] // CURTONOTUM / sternithrix / paratype ♂ n.sp. / L. TSACAS DET. 1973 [printed & handwritten] // à renvoyer à / Stuckenberg à le / place du le Holotype / unique ici L. Tsacas 1975” ( NMSA) .

Distribution ( Fig. 94 View Figs 92–96 ): Occurring in Plateau Grassland-Wooded Grassland Mosaic and Degraded Humid Forest vegetation types, in the Evergreen Rainforest biome. In the Northern Central East and South East biogeographical zones and Humid bioclimatic zone ( Figs 105–107 View Figs 105–107 ; Tables 1–3; Appendix II). Stuckenberg’s specimen label refers to site 28 in his unpublished report of his second Madagascan Expedition (1957–1958) (Kirk-Spriggs in press). The entry for 1 April 1958 reads: “(28) ANTANAMBE – night stop and some collecting.”