Thraulus (Thraulus) sp. A

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

Thraulus (Thraulus) sp. A

Figs 21 , 22 , 23

Material examined.

• Papua New Guinea, nymph on slide, Madang Province, Keki, Adalbert Mts , 400 m, 29.XI.2006, 04°43.058'S, 145°24.437'E, Binatang Boys col [PNG 119], GBICH 01223091 ( MZL) .

Diagnosis.

Nymph. Labrum trapezoidal; ventral side of the labrum with only scattered stout setae; labial palp with segment III> 4 × as long as base width. Posterior margin of abdominal segment VI – VII with well-developed denticles.

Colouration.

Femur whitish, with distal 1 / 3 greyish; forelegs greyish along the dorsal margin. Tibia whitish, apex greyish. Tarsi yellowish.

Description.

Head. Labrum trapezoid (Fig. 21 A ). Ratio labrum width / clypeus width 1.07. Ratio labrum width / insertion width 1.52. Medial emargination shallow with flat denticles. Proximal row of setae simple, shifted to distal margin (Fig. 21 B ). Number of setae on proximal row ~ 30. Distal row of setae present, simple. Median part of labrum in ventral view with only scattered stout setae. Mandibles. Outer margin with row of setae on distal 2 / 3. Ending of the row before incisor. Right mandible with eight setae below the mola (Fig. 21 C ). Maxillae. Posterior margin of cardo with very few hair-like setae and a long and stout seta in submarginal position. Proximo-lateral margin of stipes with a single long and stout seta. Apical-ventral row with 26 pectinate setae. Maxillary palps lost (Fig. 21 D ). Labium. Labial palp segment II 0.87 as long as segment I. Labial palp segment III 0.89 as long as segment I (Fig. 21 E ). Segment I inner margin with five stout setae, outer margin with eight stout setae. Segment II outer margin with two stout setae. Segment III dorsal face with eight stout setae. Segment III 4.40 × as long as width base. Hypopharynx. Apex of superlingua truncate (Fig. 21 F ).

Thorax. Dorsal margin of femur with a row of long, stout, pointed setae (Fig. 22 A ); irregular submarginal row on fore femur, regular on mid femur (Fig. 22 B ), absent on hind femur; ventral margin with short, stout setae and a submarginal row of long, pointed stout setae, except on hind leg where those on ventral margin are short and blunt; central area of upper surface with few long, pointed setae. Fore tibia with several rows of numerous mostly feathered setae on ventral margin; outer margin of fore tibia with few hair-like setae; middle tibia with two rows of long, simple or feathered, pointed setae on ventral margin, outer margin with few hair-like setae; hind tibia with a row of simple short, thin setae on ventral margin, upper and lower surface covered with simple and feathered setae, outer margin with short and long pointed stout setae. Tarsal claw straight with eight or nine denticles progressively larger, with a palisade of four small denticles at apex (Fig. 22 C ).

Abdomen. Gills lost. Posterior margin of terga VI – IX with denticles (Fig. 23 A – D ). Posterior margin of terga V with minute denticles (Fig. 23 E ). Posterolateral projections present on segments VII – IX.

Figures

Figure 21. Thraulus (Thraulus) sp. A. Nymphal mouthparts. A. Labrum, dorsal view; B. Emargination of the labrum; C. Right mandible; D. Maxilla; E. Labium; F. Superlingua of hypopharynx. Scale bars: 200 µm (A, C, D); 50 µm (B); 100 µm (E, F)

Figure 22. Thraulus (Thraulus) sp. A. Thorax. A. Fore femur; B. Mid femur; C. Claw. Scale bars: 200 µm (A, B); 50 µm (C).

Figure 23. Thraulus (Thraulus) sp. A. Abdomen. A. Posterior margin of tergite IX; B. Posterior margin of tergite VIII; C. Posterior margin of tergite VII; D. Posterior margin of tergite VI; E. Posterior margin of tergite V. Scale bar: 50 µm.