Thraulus (Masharikella) samueli, Sartori & Salles, 2025

Sartori, Michel & Salles, Frederico F., 2025, The Leptophlebiidae of New Guinea (Ephemeroptera, Choroterpinae, Thraulini), ZooKeys 1245, pp. 41-175 : 41-175

publication ID	https://doi.org/10.3897/zookeys.1245.141723
publication LSID	lsid:zoobank.org:pub:7160C34D-C437-4469-9A47-91AB5B9DFB05
DOI	https://doi.org/10.5281/zenodo.15923186
persistent identifier	https://treatment.plazi.org/id/B1B9E9DD-1109-53B1-BCCF-3C4E9BA8A96F
treatment provided by	ZooKeys by Pensoft
scientific name	Thraulus (Masharikella) samueli
status	sp. nov.

Treatment

Thraulus (Masharikella) samueli sp. nov.

Figs 24 A View Figure 24 , 31 View Figure 31 , 32 View Figure 32 , 64 A, B View Figure 64

Material examined.

Holotype. • Papua New Guinea, male nymph on slide, National Capital District, Varirata National Park , 600 m a. s. l., 09°26.13'S / 147°22.09'E, 16.XII.2007, Balke and Sagata col [PNG 159], GBIFCH 01223120 ( ZSM) GoogleMaps . Paratypes. • Papua New Guinea, 4 nymphs in ethanol, GBIFCH 01523483 , 2 nymphs entirely mounted on slide, GBIFCH 01223121 , GBIFCH 01223122 , same data as holotype ( MZL) GoogleMaps .

Nymph.

Body length, male: 4.5–4.8 mm; female: 4.9–5.2 mm.

Diagnosis.

Tarsal claw straight, without teeth; apical ventral row of maxilla composed of 16–20 pectinate setae; posterior margin of abdominal segment IX with minute denticles; posterolateral projections of the abdomen present on segments VIII – IX only.

Colouration.

Head. Yellowish brown, darker between ocelli. Triangular brown mark present on inner margin of compound eye. Antenna yellowish. Compound eye lower portion black, upper portion dark brown, not rounded but oblique and elongated. Mouth parts yellowish. Thorax. Pronotum yellowish washed with greyish brown laterally, irregular brown mark close to median line. Mesonotum yellowish washed with greyish laterally; distal half of costal field of fore wing pad orangish. Metanotum yellowish washed with greyish laterally. Femur yellowish white, dorsal surface apically washed with orange (Fig. 24 A View Figure 24 ). Tibia whitish, washed with brown on dorsal surface. Tarsi yellowish white. Abdomen. Terga orangish with dark brown rectangular marks laterally on segments I to VI, subtriangular on segment VII and IX, segment VIII entirely dark brown. Sterna uniformly whitish becoming yellowish on the last segments. Gills purplish black. Terminal filaments yellowish white washed with orange proximally.

Description.

Head. Labrum cordiform (Fig. 31 A View Figure 31 ). Ratio labrum width / clypeus width 0.89–0.98. Ratio labrum width / insertion width 1.22–1.24. Medial emargination shallow with flat denticles. Proximal row of setae present, simple. Number of setae on proximal row ~ 16–37. Distal row of setae present, simple. Median part of labrum in ventral view with stout setae in row (Fig. 31 B View Figure 31 ). Mandibles. Outer margin with middle and distal tuft of setae. Right mandible with 6–11 setae below mola (Fig. 31 C View Figure 31 ). Maxillae. Posterior margin of cardo with few hair-like setae and a long and stout seta in submarginal position. Proximo-lateral margin of stipes with a single stout and medium size seta. Apical-ventral row with 16–20 pectinate setae. Maxillary palp segment II 0.79–0.92 as long as segment I. Maxillary palp segment III 0.62–0.68 as long as segment I (Fig. 31 D View Figure 31 ). Stout setae on outer margin of segment I absent. Segment II inner margin with two or three stout setae. Segment II outer margin without stout setae. Segment III inner margin with 2–4 stout setae, dorsal surface with few setae at apex. Segment III 1.5–2.0 × as long as base width. Labium. Labial palp segment II 0.72–0.76 as long as segment I. Labial palp segment III 0.79–0.92 as long as segment I. Segment I inner margin with 7–12 stout setae, outer margin with 8–12 stout setae. Segment II outer margin without or with one or two stout setae. Segment III dorsal face with five or six stout setae. Segment III 3.0–3.67 × as long as base width. Hypopharynx. Apex of superlingua emarginated (Fig. 31 E View Figure 31 ).

Thorax. Dorsal margin of femur with a row of long, stout, pointed setae; incomplete submarginal row, sometimes with scattered long, pointed setae; ventral margin with short, blunt, stout setae; central area of upper surface without setae (Fig. 32 A – B View Figure 32 ). Inner margin of fore- and mid- tibia covered with several rows of simple and feathered setae; inner margin of hind tibia with several rows of simple and feathered setae; outer margin of fore- and mid- tibia naked, with a row of stout, pointed setae on hind tibia, especially developed in the distal half. Tarsal claw straight. Denticles absent (Fig. 32 C View Figure 32 ).

Abdomen. Gill I dorsal lamella narrow and lanceolate, ventral lamella shaped as other gills (Fig. 32 E View Figure 32 ). Gills II – VII with dorsal and ventral lamellae of the same size. Ventral lamella of gill I with ~ 25 long filaments; dorsal and ventral lamellae of gills II – VI with ~ 40 very long filaments each (Fig. 32 F View Figure 32 ); gill VII with ~ 20 filaments on each lamella. Posterior margin of terga IX with small denticles (Fig. 32 D View Figure 32 ). Posterior margin of terga V – VIII without denticles. Posterolateral projections on segments VIII – IX.

Eggs. General shape elongated. Size ca 185 μm × 80 μm. Chorionic surface with irregular longitudinal ridges connected transversally, forming rectangular smooth areas in-between (Fig. 64 A View Figure 64 ). On each pole arise basally six equally distant pairs of long, apically hooked attachment structure (Fig. 64 B View Figure 64 ). Micropyle not visible.

Derivatio nominis.

This species is dedicated to Samuel Sartori, grandson of the first author.