Curtonotum scambum Klymko & Marshall, 2011

Klymko, John & Marshall, Stephen A., 2011, Systematics of New World Curtonotum Macquart (Diptera: Curtonotidae) 3079, Zootaxa 3079 (1), pp. 1-110 : 86-88

Curtonotum scambum Klymko & Marshall , sp. n.

Figures 155–162 , and 217

Etymology. From Latin, scambus, meaning bow-legged, referring to the bent hind femora of this species.

Diagnosis. Curtonotum scambum can be distinguished from congeners outside of the C. vulpinum species complex by the basal bend in the hind femur. The extent of infuscation apically in r 1 and r 2+3 is also more limited than in wings of similarly marked species except C. gracile , its proximal margin at or just anterior of level of crossvein dm-cu.

Description. Matches description for C. hendelianum , except as follows. Length 6.3–8.1 mm. Frons with dark brown ground colour extending to lateral margin, iridescence purple or green, width 1.3–1.4 times length, parallel sided to slightly narrower ventrally. Proclinate seta ventral to major reclinate seta, minor reclinate seta ventral and medial to major reclinate seta. Face and parafacial ground colour medium brown, parafacial slightly broader, eye height 12.0–17.5 gena height. Clypeus with medium brown ground colour, prementum lightly grey microtomentose. Legs yellow-orange, grey microtomentose throughout, ctenidial setae 6–8, mid and hind femora without darkened apices, hind femur with ventral concavity on proximal half, with 1–2 subapical dorsal setae. Area of dark brown infuscation apically in r 1 and anterior third to half of r 2+3, the anterior margin of this infuscation at or slightly proximal of the level of crossvein dm-cu; r 1 otherwise dark brown infuscate on anterior quarter to half to level of crossvein r-m; r 2+3 lightly brown infuscate in broad apical area, membrane around r 4+5 and m 1 narrowly brown infuscate. Tergite 3 and 4 with broad medial and lateral vittae, these wider on tergite 4; brown microtomentum not limited to anterolateral corners, extending to posterior margin and along anterior margin in tergite 5 (nearly to medial vitta in some specimens).

Male terminalia: Sternite 5 often with invaginate area of weak sclerotization on distal margin (this absent in one male from Iquitos, Peru), weakly sclerotized area without setulae; tergite 6 weakly sclerotized, somewhat desclerotized medially; tergite 7 very short, dorsal length less than one-fifteenth epandrial dorsal length; both sternite 6 and 7 well separated into right and left portions, right and left portion of sternite 6 broad and well sclerotized, right portion slightly bulging on left, left portion more heavily sclerotized proximally; right portion of sternite 7 relatively long, subequal in length to right portion of sternite 6. Epandrium relatively large, with large posterolateral lobe (particularly evident in posterior profile), with scattered setulae, longest of these on posterior margin of lateral lobe; surstylus laterally articulating with and medially fused to epandrium, broadening distally, lateral margin rounded in posterior profile, distomedial corner bending ventrally, exposing ventral face in posterior profile, minutely setulose marginally and medially; area adjacent to postgonite concave. Cercus longer than high, ventral margin flat, posterior margin broadly rounded, longest cercal setulae shorter than longest epandrial setulae. Hypandrium with broad, somewhat peaked dorsobasal lobe, posterior bridge produced ventrally and slightly posteriorly, apically arm with slight dorsal bend then strong ventral bend, with 1–2 medially oriented setulae proximal to postgonite, broadly fused distally (point of fusion demarked by a suture); postgonite narrowing into slightly upturned minutely setulose apex, obscured by surstylus in lateral profile. Phallapodeme with relatively small, anteriorly bulging “fan”, margin opposite fan convex basally, concave distally; basiphallus very elongate, weakly sclerotized basally, slightly S-shaped in dorsal profile subapically, broadening slightly apically; distiphallus base elongate, flattened and twisted, broad narrow edge flaring ventrally and to left, apex bilobed, lobes of subequal length, left lobe at base at ca. 45˚ angle from phallus axis, bending distally at midpoint, with ventral sclerotized region bifurcate basally, left portion short, right portion elongated, extending ca. three-quarters distance to apex, membranous portion broad, with scaly texture ventrally and fine spinules dorsally, right lobe narrowly sclerotized, sclerotization extending ca. three-quarters distance to apex, otherwise membranous, dorsal surface with fine short spinules. Ejaculatory apodeme outside of basiphallus, with slight expansion and small pores basally.

Female terminalia: Ovipositor slender and elongate (as in Figure 202 ). Sternite 5 length 1.7–2.4 times width, sternite 6 length 1.6–1.7 times width, tergite 6 slightly desclerotized medially on proximal half. Tergite 7 desclerotized medially. Tergite 8 and sternite 8 weakly sclerotized proximally. Sternite 8 with broad heavily sclerotized margin on apical half, heavily sclerotized area without setulae or microtrichia, surface slightly concave apically, weakly arrow-shaped. Spermatheca elongate, rugose, with minute scattered protuberances, the relative length and density of protuberances varying within species. Ventral receptacle with broad-based conical neck and bent, concave dish-shaped apex, duct with minute longitudinal wrinkles.

Type material. Holotype: ♂: PERU. Loreto: Iquitos , iii–iv.1931, R.C. Shannon ( USNM) . Paratypes: PERU. Loreto: ♂, ♀, Callicebus Res. Station, Mishana, Rio Nanay , 25 km SW Iquitos, tropical west forest, 120 m, 10– 17.i.1980, J.B. Heppner ( USNM) ; 2♂, 6♀, Iquitos , iii–iv.1931, R.C. Shannon ( USNM) .

Figures

FIGURES 155–162. Curtonotum scambum Klymko & Marshall, sp. n. 155. Male terminalia, left lateral. 156. Male terminalia, posterior. 157. Distiphallus, dorsal. 158. Female sternite 8, ventral. 159. Female sternite 10, ventral. 160. Spermatheca. 161. Ventral receptacle. 162. Hind femur, anterior.

FIGURES 195–202. Curtonotum punctithorax Fischer. 195. Male terminalia, left lateral. 196. Distiphallus, dorsal. 197. Male terminalia, posterior. 198. Female sternite 8, ventral. 199. Female sternite 10, ventral. 200. Spermatheca. 201. Ventral receptacle. 202. Ovipositor, left lateral.