Curtonotum gracile Klymko & Marshall, 2011

Klymko, John & Marshall, Stephen A., 2011, Systematics of New World Curtonotum Macquart (Diptera: Curtonotidae) 3079, Zootaxa 3079 (1), pp. 1-110 : 88-91

Curtonotum gracile Klymko & Marshall , sp. n.

Figures 163–169

Etymology. From Latin, gracilis, meaning slender, referring to the elongate slender basiphallus of this species.

Diagnosis. Distinguished from all congeners but C. desperatum by the combination of a dark brown palpus and medium to dark brown face, a moderately tall gena (eye height to gena height ration is 10.5–12.0), an orangebrown frons free of vittae, and a vibrissa that is no longer than adjacent subvibrissae.

Characters to distinguish C. gracile from C. desperatum are provided in the diagnosis of the latter species.

Description. Length: 7.0– 8.5 mm.

Head: Frons orange-brown with green-purple iridescence (visible only from oblique angle), moderate bulge ventrally and scattered pale setulae, width 1.3–1.4 times height, parallel sided, lateral margin silver microtomentose. Ocellar triangle and narrow lateral strip gold microtomentose, microtomentum not extending anterior of anterior ocellus, lateral microtomentose strip extending from median occipital sclerite to slightly anterior of proclinate seta. Proclinate seta ca. two-fifths sagittal distance between anterior ocellus and ventral margin of frons, anterior to major reclinate seta; minor reclinate seta anterior to and medial of major reclinate seta. Face with dark to medium brown ground colour, colour paler lateral of frontogenal suture, vibrissa subequal in length to adjacent subvibrissals. Parafacial moderately broad, gena relatively narrow, former densely silver microtomentose with brown-yellow ground colour, latter lightly microtomentose, ground colour similar, slightly darker posteriorly, eye height 10.5–12.0 times gena height. Clypeus silver microtomentose with medium brown ground colour; palpus brown microtrichose with dark brown ground colour; prementum with dark brown ground colour, lightly silver microtomentose laterally, bare and shiny medially. Scape and pedicel silver microtomentose with orange-brown ground colour; first flagellomere silver microtrichose, ground colour orange-brown on proximal ca. third, otherwise dark brown.

Thorax: Colouration of and patterning in microtomentum difficult to assess due to somewhat degraded nature of the two specimens available. Specimens in better condition may differ from this description. Grey microtomentose (except grey-brown microtomentose scutellum). Scutum moderately arched, each scutal, postpronotal, and anepisternal seta and setula with grey-brown spot around socket. Scutum with 2 pairs of lateral vitta, these well defined posteriorly, their full extent impossible to assess with specimens available. Postpronotal lobe with 5 setae, 2 anterior-most setae and the posterior-most seta relatively weak, other 2 setae strong, subequal in length. Anepisternum with 2–3 strong and 1–2 moderate setae (female specimen with 2 strong and 2 moderate, male specimen with 3 strong and 1 moderate); katepisternum with 2 prominent lateral setae, anterodorsal seta relatively weak, linear tuft of setulae under fore coxa orange-yellow. Area below and behind posterior spiracle bare (without fringe of setulae); minute setulae on ventral half of meron present.

Legs: Coxae densely 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 legs orange-yellow, femora slightly darker of apical ca. third. Fore femur with 5 posterodorsal setae, 5–7 ctenidial setae, these relatively thick and subequal in length to adjacent setulae; mid femur with 6–8 anterior setae; hind femur with single subapical dorsal seta. Mid tibia with 2 strong, 1 moderate, and several weak ventral apical setae, the moderate seta between the strong setae. Mid and hind tarsomere 5 without short cuneiform setae on anteroventral margin.

Wing: As in C. atlanticum except as follows. Costal cell pale brown infuscate, proximal limit of area of dark brown infuscation in r 1 and r 2+3 at ca. two-thirds distance from R 1 apex to level of dm-cu in male specimen, to just proximal to level of dm-cu in female specimen.

Abdomen: Grey microtomentose except where noted, ground colour dark brown. Tergite 1 lightly microtomentose, visible only from oblique angle. Tergite 2 medium brown microtomentose dorsally on posterior ca. half. Tergite 3 brown microtomentose dorsally on distal ca. two-thirds, with narrow lateral and moderately broad medial brown vittae. Tergite 4 similar to tergite 3 but brown microtomentose dorsally on distal ca. two-fifths, lateral vitta moderately broad. Tergite 5 similar to tergite 3 but brown microtomentose of dorsal ca. fifth and without lateral vitta (small indentation present laterally on anterior margin of dorsal brown microtomentose area).

Male terminalia: Sternite 5 truncate posteriorly, with slight desclerotized invagination on posterior margin, area of desclerotization setulose; tergite 6 moderately sclerotized, desclerotized medially; tergite 7 relatively short, dorsal length ca. 0.3 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. one-third as long as right portion of sternite 6. Epandrium relatively small, with large posterolateral lobes (particularly evident in posterior profile), scattered setulae (longest on posterolateral lobe); surstylus laterally articulating and medially fused with epandrium, posteriorly bending medially around postgonite, minutely setulose on medial face and ventral margin, ventral face concave adjacent to postgonite, in lateral profile posteroventral margin slightly concave, posterior margin flat, in posterior profile medial margin straight, parallel to medial margin of opposite surstylus. Cercus stout, ventral margin flat, posterior margin broadly rounded, longest cercal setulae shorter than longest epandrial setulae. Hypandrium with broad-based, triangular dorsobasal lobe, posterior bridge projecting anteroventrally, hypandrial arm with slight dorsal bend at posterior margin of epandrium, with 2 venteromedially oriented setulae proximal to postgonite, broadly fused apically to opposite hypandrial arm; postgonite with medial margin straight, apex upturned, minutely setulose dorsally. Phallapodeme with relatively large, anteriorly bulging “fan”, margin opposite fan convex basally, concave distally; basiphallus weakly sclerotized basally, extremely elongate; distiphallus base very slender, straight, and elongate, bowed slightly dorsally, apex bilobed, left lobe longer, at ca. 45˚ angle from axis of phallus, well sclerotized medially on ventral face on proximal half, ventral face otherwise moderately sclerotized and with pebbled texture, well sclerotized on dorsolateral margin on basal third, this sclerotized plate sharply pointed and incurved apically, ventrolateral margin with well-sclerotized antrorse teeth (these occluded in dorsal profile by somewhat inflated, membranous dorsal surface), dorsal face membranous, with patch of broad-based, stout spinules on distal half and fine spinules on proximal half, apex broadly rounded, right lobe well sclerotized medially on ventral face on proximal half, ventral face otherwise lightly sclerotized, with pebbled texture, dorsal surface moderately sclerotized medially, otherwise lightly sclerotized, with pebbled texture, contracted subapically, apex a rounded knob. Ejaculatory apodeme in single available male specimen apparently lost during dissection.

Female terminalia: Ovipositor slender and elongate (as in Figure 202 ). Sternite 5 length 2.4 times width, sternite 6 length 1.6 times width. Tergite 6 desclerotized medially on proximal ca. third Tergite 7 desclerotized medially. Tergite 8 and sternite 8 weakly sclerotized proximally. Sternite 8 broadly pointed at apex, with extensive heavy sclerotization on posterior half, area of heavy sclerotization free of microtrichia. Sternite 10 elongate, heavily sclerotized medially and with antrorse spinules medially, proximal margin heavily sclerotized and bent dorsally, distal half broad. Spermatheca elongate, very finely rugose with minute protuberances scattered along raised ridges. Ventral receptacle with squat, well-sclerotized, oblique neck, bent at base of head, head a circular disk, duct with minute transverse wrinkles.

Type material. Holotype: ♂: BRAZIL. Pará: Cachimbo, x.[1]955, Pe. Pereira ( MZSP) . Paratype: ♀: BRA- ZIL. Pará: Cachimbo, x.[1]955, Pe. Pereira ( MZSP) .

Figures

FIGURES 163–169. Curtonotum gracile Klymko & Marshall, sp. n. 163. Male terminalia, left lateral. 164. Male terminalia, posterior. 165. Distiphallus, dorsal. 166. Sternite 8, ventral. 167. Sternite 10, ventral. 168. Ventral receptacle. 169. Spermatheca.

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.