Nonnullidens sp. B

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

Nonnullidens sp. B

Figs 58 , 59

Material examined.

• Papua New Guinea, one nymph on slide, GBIFCH 01223128 , Western Highlands Province, Simbai , 1800–2000 m, 25.II.2007, 05°16.330'S, 144°33.176'E, Kinibel col [PNG 133] ( MZL) .

Diagnosis.

Nymph. Labrum trapezoidal; dorsal face of labrum with multiple rows in distal position; femora pale brown with two transverse dark brown bands in middle and at apex.

Colouration.

Femur yellowish, a medium brown transversal band in the middle, apex medium brown (Fig. 59 A – B ). Tibia yellowish, apex dark brown. Tarsi yellowish. Gills greyish brown.

Description.

Head. Labrum trapezoid (Fig. 58 A ). Ratio labrum width / clypeus width 1.17. Ratio labrum width / insertion width 1.46. Medial emargination narrow with flat denticles. Proximal row of setae present, simple. Number of setae on proximal row ~ 106. Distal row of setae multiple. Median part of labrum in ventral view with scattered thin setae (Fig. 58 B ). Mandibles. Outer margin with row of setae on distal 1 / 2. Ending of the row near incisor. Right mandible with nine setae below the mola (Fig. 58 C ). Maxillae. Posterior margin of cardo broken. Proximo-lateral margin of stipes with a bunch of ~ ten stout short and medium size setae. Apical-ventral row with 30 pectinate setae. Maxillary palp segment II 0.76 as long as segment I. Maxillary palp segment III 0.71 as long as segment I (Fig. 58 D ). Stout setae on outer margin of segment I absent. Segment II inner margin with two stout setae, outer margin without stout setae. Segment III inner margin with one stout seta, dorsal surface half covered with setae. Segment III 1.50 × as long as base width. Labium. Labial palp segment II 0.79 as long as segment I. Labial palp segment III 0.65 as long as segment I (Fig. 58 E ). Segment I inner margin with 14 stout setae, outer margin with 15 stout setae. Segment II outer margin with nine stout setae. Segment III dorsal face with two stout setae. Segment III 2.73 × as long as base width. Hypopharynx. Apex of superlingua truncate (Fig. 58 F ).

Thorax. Dorsal margin of femur with a row of very long, thin, pointed setae; regular submarginal row of pointed setae as long as or shorter than those on the dorsal margin, multiple submarginal rows on fore femur (Fig. 59 A ); ventral margin with short, pointed setae and an irregular submarginal row of long, pointed setae, except on hind femur where they are short and stout; central area of upper surface with very long pointed setae on fore femur, long and short on middle femur and short on hind femur (Fig. 59 B ). Fore tibia with two or three rows of long simple or feathered setae on ventral margin, dorsal margin with numerous hair-like setae; middle tibia with a row of short, simple, pointed setae on ventral margin and a submarginal row of long, simple setae, outer margin with numerous hair-like setae; hind tibia with a marginal row of simple short, thin setae and a submarginal row of long to very long simple setae on ventral margin, outer margin with long to very long pointed setae and numerous hair-like setae. Tarsal claw slightly hooked, with five or six denticles progressively larger, except distal much larger (Fig. 59 C ).

Abdomen. Gill I with both lamellae. Gills II – VII with dorsal and ventral lamellae, ventral lamella smaller. Gill I with nine or ten filaments on dorsal lamella and five or six on ventral lamella, gills II – VI with 11–12 filaments on dorsal lamella and six or seven on ventral lamella (Fig. 59 E ), gill VII with nine or ten filaments on dorsal lamella and four or five on ventral lamella. Posterior margin of terga IX with denticles (Fig. 59 D ). Posterior margin of terga V – VIII without denticles. Posterolateral projections present on segments VIII – IX.

Figures

Figure 58. Nonnullidens sp. B. 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 – E); 50 µm (B); 100 µm (F).

Figure 59. Nonnullidens sp. B. Thorax and abdomen. A. Fore femur; B. Hind femur; C. Claw; D. Posterior margin of tergite IX; E. Gill IV. Scale bars: 200 µm (A, B); 100 µm (C); 50 µm (D).