Curtonotum flavisetum Klymko & Marshall, 2011

Klymko, John & Marshall, Stephen A., 2011, Systematics of New World Curtonotum Macquart (Diptera: Curtonotidae) 3079, Zootaxa 3079 (1), pp. 1-110 : 72-75

Curtonotum flavisetum Klymko & Marshall , sp. n.

Figures 122–130

Etymology. From Latin, flavus, meaning yellow, and seta, meaning seta; referring to the yellow setae of the mid coxa of this species.

Diagnosis. Curtonotum flavisetum specimens can be distinguished from most C. taeniatum and C. tumidum specimens by the prominent pale yellow seta at the posteroventral corner of the katepisternum (black in the other two species) and the almost complete absence of dark setae medially on the mid coxa (two specimens, one from Cachuela Esperanza, Bolivia, and one from Matto Grosso, Brazil, have a single dark seta medially on both mid coxae; otherwise in all specimens available these setae are entirely pale yellow [in the other two species there are generally more than three dark setae medially on the mid coxa]). Males can be readily distinguished by their expanded and densely setulose sternite 5 and very stout phallus, females can be distinguished by their ventral receptacle which has a more elongate neck.

Description. Length: 9.8–9.9 mm.

Head: Frons orange-yellow, slightly to much darker medially, with moderate bulge ventrally and scattered dark setulae, width 1.3–1.4 times length, parallel sided, lateral margin narrowly silver microtomentose. Ocellar triangle, broad medial vitta, and narrow lateral strip microtomentose, former two with white microtomentum, latter with yellow-white microtomentum, microtomentum of ocellar triangle confluent with medial vitta, narrow lateral strip extending from median occipital sclerite to just beyond proclinate seta. Proclinate seta at ca. one-fifth to one-third sagittal distance from anterior ocellus to ventral margin of frons, anterior to and slightly lateral of major reclinate seta; minor reclinate seta anterior to and slightly medial of major reclinate seta. Face silver microtomentose, ground colour pale to medium yellow-brown; vibrissa slightly to much larger than adjacent subvibrissals, vibrissa and several subvibrissals yellow-orange. Parafacial and gena moderately broad, former silver microtomentose, latter yellow microtomentose, ground colour of both pale to medium yellow-brown, eye height 9.5–11.1 gena height. Clypeus, palpus and prementum with orange-yellow ground colour, former two densely gold microtomentose and microtrichose, respectively, latter lightly gold microtomentose. Scape, pedicel and first flagellomere with orangeyellow ground colour, former two very lightly silver microtomentose, latter densely yellow-white microtrichose. Setulae on pedicel black dorsally, orange ventrally.

Thorax: Ground colour orange-yellow, gold microtomentose on scutum, medium brown microtomentose on scutellum, white microtomentose on pleura. Scutum moderately arched, each scutal, postpronotal, scutellar and anepisternal (at least on dorsal half) seta and setula with dark spot around socket. Scutum with pair of narrow vittae for entire length, these quite faint and best seen in low magnification under good lighting. Postpronotal lobe with 3 setae, anterior and posterior setae ca. half length of central seta, posterior seta sometimes somewhat reduced; notopleuron setulose; scutellum with 2 pairs of marginal setae. Anepisternum with 3 or 4 large subequal setae and 3 or 4 smaller setae on posterior half; katepisternum with 1 prominent lateral seta; linear tuft of setulae under fore coxa pale yellow; setae in posteroventral corner pale yellow. Fringe of pale yellow setulae ventral and posterior of posterior spiracle; minute setulae present on ventral half of meron.

Legs: Legs pale orange-yellow in ground colour, coxae heavily white microtomentose, legs otherwise lightly so. Setulae of fore coxa orange-yellow, often several larger black setae in posterolateral corner. Mid coxa medially with pale yellow setae (single specimens from Cachuela Esperanza, Bolivia, and Matto Grosso, Brazil, with single dark seta on both mid coxae). Chaetotaxy of femora, tibia and tarsi black except for scattered pale setulae on ventral surface of femora, including all setulae on the anterior surface of fore femur (both dorsal of and proximal to the ctendial comb), and very dense, regularly spaced transverse rows of setulae anteroventrally on apical half of fore tibia and similar setulae on fore tarsomere 1, these dark orange-brown. Fore femur with 3–5 posterodorsal setae and 6–8 moderately stout black ctenidial setae, these constrasting with adjacent pale setulae; mid femur with 5–7 anterior setae; hind femur with 2 subapical dorsal setae. Mid tibia with 2 very strong, 1 moderately strong, and several weaker apical ventral setae, the moderately strong seta between the strong setae. Mid and hind tarsomere 5 without short cuneiform setae on anteroventral margins.

Wing: Similar to C. tumidum .

Abdomen: Ground colour orange-yellow. Tergite 1 lightly gold microtomentose, best seen from oblique angle, tergite 2 similar, ground colour and microtomentum very slightly darker apically. Tergite 3 with slightly darker ground colour and microtomentum on medial vitta, this vitta narrow proximally, abruptly widening to cover dorsal surface on the posterior half, otherwise slightly gold microtomentose. Tergite 4 with moderately dark brown central vitta (darker posteriorly), this vitta narrow proximally, abruptly broadening to cover dorsal surface on distal ca. third, otherwise moderately gold microtomentose. Tergite 5 similar to tergite 4 except gold microtomentum denser and medial vitta darker, wider anteriorly, and abruptly broadening on distal ca. quarter.

Male terminalia: Sternite 5 broad, with dense yellow setulae, posterior margin truncate, with deeply invaginate area of desclerotization on posterior margin, area of desclerotization without setulae; tergite 6 moderately sclerotized, with area of desclerotization dorsally on proximal half, tergite 7 relatively long, dorsal length ca. 1.7 times epandrial dorsal length; sternite 6 and 7 separated into right and left portions, sternite 6 long, moderately sclerotized, left portion more heavily sclerotized along proximal margin; right portion of sternite 7 relatively short, ca. 0.3 times length of right portion of sternite 6. Epandrium relatively small, with scattered setulae, these longest in posteroventral corner, and very long, bare (free of microtrichia and setulae) posteroventral extensions, these fused medially posterior to cerci, posterior edge of sclerotization ending at distinct rough patch proximal to surstyli; surstylus relatively small, separated from epandrium by sclerotized rough patch, ventral face and margins setulose, slightly concave directly opposite of postgonite ventrally, lateral margins setulose dorsally, in lateral profile ventral margin flat, with slight dorsal bend on distal half, sharp dorsal bend distally, posteroventral margin concave, in posterior profile lateral margin broadly rounded, tightly rounded apically, distal margin concave, medial margin concave. Cercus elongate, posteroventrally produced, ventral margin concave, longest cercal setulae much longer than longest epandrial setulae. Hypandrium with low, rounded dorsobasal lobe, posterior bridge projecting slightly ventrally, hypandrial arm bending more than 90˚ at hind margin of epandrium, with deep invagination on ventral margin at bend, 2 ventrolaterally oriented setulae distal to bend and anteriorly oriented process on medial margin distally, not fused apically to opposite hypandrial arm; postgonite minutely setulose dorsally, with small, venteromedial projection at apex. Phallapodeme with large, anteriorly bulging “fan”, margin opposite fan convex basally, concave distally; basiphallus weakly sclerotized basally, very thick, moderately elongate, with laterally expanded dorsal lobe distally; distiphallus fused to basiphallus, base moderately short, laterally compressed, distiphallus bilobed, their bases stacked dorsoventrally, ventral lobe extending to left perpendicular to axis of phallus, longer than dorsal lobe, well sclerotized on distal margin, with coarse pebbled texture, pointed apically, dorsal lobe extending posteriorly in plane of phallus, well sclerotized dorsally below loose dorsal membrane, with fine pebbled texture throughout, pointed apically. Ejaculatory apodeme outside of basiphallus, expanded and with small pores basally.

Female terminalia: Sternite 5 length 2.3–2.6 times width, sternite 6 length 1.5 times width. Ovipositor slender (as in Figure 202 ). Tergite 7 desclerotized medially. Sternite 8 length ca. 2.8–3.0 times width, heavily sclerotized in apical half, apex with slightly concave surface, rounded/truncate in profile, with broad marginal area free of microtrichia. Tergite 8 and sternite 8 weakly sclerotized proximally. Sternite 10 heavily sclerotized and with antrorse spinules medially, area of sclerotization with flared proximal margin and with slight dorsal bend, profile narrow on proximal half, broader on distal half. Spermatheca elongate with small clear cap at tip, papillose, papillae minute broad-based spines. Ventral receptacle with heavily sclerotized elongate neck and reflexed, lightly sclerotized donut-shaped apex, bend at midway point between neck base and donut-shaped apex, duct with fine longitudinal wrinkles.

Comments. One male specimen from Matto Grosso, Brazil, has the right vibrissa black and left vibrissa (or at least the base of this seta that remains) yellow-orange. One greasy specimen from Cachuela Esperanza, Bolivia, appears to have a very darkly pigmented head. Three other specimens from the same locality have varying amounts of dark brown to black colouration in the ground colour of the clypeus, prementum and palpus. In two of these specimens these markings are quite mottled and asymmetrical. Given the species’ propensity to darken when greasy and variable amounts of dark colouration in the other specimens it is assumed these dark markings are an artifact of preservation and not natural markings. A female specimen from Matto Grosso, Brazil, has dark brown (not black) setulae on the anteroventral face of the fore femur.

Type material. Holotype: ♂: BRAZIL. Mato Grosso: Villa Murtinho , 1.iv.1922, J.H. Williamson ( USNM) . Paratypes: BOLIVIA. Beni: ♀, Beni-Gebiet, Guayaramerin , 150 m, 10.v.1954 , ♂, ♀, 15.v.1954, 3♂, 17.v.1954, all W. Forster (all ZSMC) . Pando: 2♂, 3♀, Cachuela Esperanza , iii, W. Mann, Mulford Biological Exploration 1921– 1922 ( USNM) . BRAZIL. Mato Grosso: ♀, Villa Murtinho , 1.iv.1922, J.H. Williamson ( USNM) .

Figures

FIGURES 122–125. Curtonotum flavisetum Klymko & Marshall, sp. n. 122. Male terminalia, left lateral. 123. Male terminalia, posterior. 124. Distiphallus, dorsal. 125. Male sternite 5,ventral.

FIGURES 126–130. Curtonotum flavisetum Klymko & Marshall, sp. n. 126. Head, anterior. 127. Female sternite 8, ventral. 128. Female sternite 10, ventral. 129. Ventral receptacle. 130. 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.