Curtonotum adusticrus Klymko & Marshall, 2011

Klymko, John & Marshall, Stephen A., 2011, Systematics of New World Curtonotum Macquart (Diptera: Curtonotidae) 3079, Zootaxa 3079 (1), pp. 1-110 : 48-50

Curtonotum adusticrus Klymko & Marshall , sp. n.

Figures 66–69

Etymology. From Latin, adustus, meaning swarthy, and crus, meaning leg; referring to the dark legs of this species.

Diagnosis. Distinguished from all congeners by the combination of a wing with extensive dark infuscation in r 1 and r 2+3 and around dm-cu, a dark brown palpus and face, a moderately tall gena (eye height to gena height ration is 9.0–10.6) that is distinctly taller posteriorly, a very strong vibrissa, and dark brown legs.

Description. Length: 6.0–8.0 mm.

Head: Frons dark brown with pale brown-yellow medial vitta and faint blue-green iridescence (visible only from oblique angle), slight bulge ventrally and scattered dark setulae, width 1.3–1.4 times height, slightly narrower ventrally, lateral margin silver microtomentose. Ocellar triangle and narrow lateral strip gold microtomentose, microtomentum of ocellar triangle not extending anterior of anterior ocellus, lateral microtomentose strip extending from median occipital sclerite to slightly posterior of midpoint between proclinate seta and anterior margin of frons. Proclinate seta ca. one-third to two-fifths sagittal distance between anterior ocellus to ventral margin of frons, anterior to major reclinate seta; minor reclinate seta anterior to and medial of major reclinate seta. Face with dark brown ground colour, yellow-brown lateral of frontogenal suture, frontal carina bare and shiny; vibrissa ca. 2 (Sao Paulo specimen) to several (Rio de Janeiro specimen) times longer than adjacent subvibrissals. Parafacial and gena relatively narrow, former with brown-yellow ground colour and dense silver microtomentum, latter with darker ground colour and sparser microtomentum, eye height 9.0–10.6 times gena height, gena taller posteriorly. Clypeus, prementum, and palpus dark brown in ground colour, clypeus silver microtomentose, palpus brown microtrichose, prementum sparsely silver microtomentose laterally, otherwise bare and shiny. Scape and pedicel silver microtomentose with orange-brown ground colour, first flagellomere silver microtrichose, ground colour orange-brown on proximal ca. fifth, otherwise dark brown.

Thorax: Light brown microtomentose dorsally (except dark brown microtomentose scutellum), purple-grey microtomentose laterally. Scutum moderately arched, each scutal, postpronotal, and anepisternal seta and setula with dark brown spot around socket. Scutum with 2 pairs of brown vittae, medial pair narrow, visible on entire length, lateral pair wider, evident from midpoint of presutural area to posterior margin. Postpronotal lobe with 4 setae, these progressively longer posteriorly; notopleuron without setulae; scutellum with 2 pairs of marginal setae. Anepisternum with 2 strong and 3 moderate setae (in Rio de Janeiro specimen 4 dorsal-most setae subequal in size); katepisternum with 1 prominent lateral seta; linear tuft of setulae under fore coxa medium brown. Area below and behind posterior spiracle bare (without fringe of setulae); meron bare.

Legs: Coxae densely purple-grey microtomentose, legs otherwise lightly so. Chaetotaxy black, except for very dense, regularly-spaced transverse rows of setulae anteroventrally on apical half of fore tibia and similar setulae on fore tarsomere 1, these dark brown. Ground colour of tarsomeres 1 and 2 pale yellow with dark brown apices, leg ground colour otherwise dark brown. Fore femur with 5–7 posterodorsal setae, 6–7 ctenidial setae, these relatively short and stout; mid femur with 6–8 anterior setae; hind femur with single subapical dorsal seta (Rio de Janeiro specimen with 2 on right). Mid tibia with 2 strong, 2 moderate and several weak apical ventral setae, first moderate seta between the strong setae, second posterior to them. Row of cuneiform setae present on entire anteroventral margin of mid and hind tarsomere 5.

Wing: As in C. papillatum except as follows. Alula relatively narrow. Costal cell dark brown, r 1 without area of light infuscation distal to costal, membrane around M 1 and CuA 1 narrowly medium brown infuscate.

Abdomen: Ground colour dark brown. Tergite 1 lightly grey microtomentose, visible only from oblique view. Tergite 2 dark brown microtomentose on distal ca. quarter, otherwise grey microtomentose. Tergite 3 and 4 with pair of oblong, transversely oriented, widely separated, grey microtomentose maculae on proximal half, otherwise dark brown microtomentose. Tergite 5 similar to tergite 3 and 4, but maculae much larger, their medial margins closer together, lateral margins extending nearly to margins, and posterior margin at ca. four-fifths distance from anterior margin to posterior margin.

Male terminalia: Sternite 5 truncate posteriorly, well sclerotized along posterior margin; tergite 6 poorly sclerotized, desclerotized medially; tergite 7 relatively long, dorsal length ca. 0.6 times epandrial dorsal length; sternite 6 and 7 separated into right and left portions, sternite 6 broad, well sclerotized, left portion more heavily sclerotized along proximal margin; right portion of sternite 7 short, ca. half as long as right portion of sternite 6. Epandrium relatively small, with moderate posterolateral lobe, scattered setulae including several scattered greatly enlarged setae, well-sclerotized connection ventral of cerci; surstylus laterally articulating and medially fused with epandrium, posteriorly bending medially around postgonite, minutely setulose on medial face and proximally on medial margin, in lateral profile posteroventral margin nearly flat, posterior extreme tightly rounded, in posterior profile venterolateral margin tightly rounded, ventral margin flat, medial margin concave. Cercus short to slightly elongate, posterior margin straight, sloping, ventral margin concave, longest setulae much shorter than longest epandrial setulae. Hypandrium with broad-based rounded-truncate dorsobasal lobe, posterior bridge ventrally and anteriorly produced, hypandrial arm relatively straight, with 3–4 ventrally and ventromedially oriented setulae proximal to postgonite, not fused to opposite hypandrial arm apically (no connection discernable in intact hypandrium-epandrium complex); postgonite minutely setulose dorsally, with broadly rounded, medially oriented lobe on medial margin nearly reaching to slightly overlapping with similar lobe of opposite postgonite, and smaller, more acute, dorsally setulose, upturned, apical process. Phallapodeme with relatively large, anteriorly bulging “fan”, margin opposite fan convex basally, concave distally; basiphallus elongate, weakly sclerotized basally, slightly expanded apically; distiphallus base moderately elongate, bowed slightly to left, contracted apically, apex bilobed, left lobe longer, at ca. 45˚ angle from axis of phallus, heavily sclerotized ventrally on lateral half and along lateral margin on basal ca. two-thirds, sclerotized area on lateral margin with incurving tooth distolaterally, otherwise membranous, ventral surface slightly pebbled, dorsal margin with fine spinules distally (these occurring to base in specimen from Cantareira Chapadâo, Brazil), apex broad, rounded, right lobe well sclerotized ventrally on medial half and along medial margin to apex, otherwise membranous, ventral surface smooth, dorsally with fine spinules basally (these occurring to apex in specimen from Cantareira Chapadâo, Brazil), tapering apically. Ejaculatory apodeme outside of basiphallus, elongate, pointed apically, with small pores medially, expanded basally.

Female terminalia: Unknown.

Type material. Holotype: ♂: BRAZIL. Rio de Janiero: Itatiaia , 1200 m, ii.1941 ( USNM) . Paratype: ♂: BRA- ZIL. São Paulo: Serra da Cantareira, Chapadâo, 4.1946, Barreto ( MZSP) .

Figures

FIGURES 66–69. Curtonotum adusticrus Klymko & Marshall, sp. n. 66. Male terminalia, left lateral. 67. Distiphallus, dorsal. 68. Male terminalia, posterior. 69. Head, anterior.