Thraulus Eaton, 1881

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

Genus Thraulus Eaton, 1881

Diagnosis.

Nymphs of the genus Thraulus are adequately characterised by Grant (2024): two dorsal rows of setae on the dorsal face of labrum; width of labrum subequal to width of clypeus (range: 0.81–1.07); lateral margins of clypeus parallel; posterolateral projections on abdominal segments VI – IX, VII – IX or VIII – IX; gills I – VII dissimilar; gill I composed of one or two lanceolate and long lamellae, or a dorsal lanceolate lamella and a ventral oval and fringed lamella; gills II – VII composed of two fringed lamellae along the entire margin, with some species having the basal half of lateral margin bare. Contrary to Grant (2024) the ventral side of labrum can bear not only a row of short stout setae (e. g., Fig. 12 B ) but in some species scattered stout or thin setae (e. g., Fig. 18 B ). The hypopharynx does not always bear a “ small, rounded, posterolateral projection on arms of the superlingua ”, compare for instance Fig. 21 F and Fig. 29 F .

Species composition.

The species Thraulus eatoni Grant, 2024 [ Indonesia Sulawesi], Thraulus parentalis Grant, 2024 [peninsular Malaysia], Thraulus petersorum Grant, 2024 [peninsular Malaysia, east Malaysia Sabah], Thraulus semicastaneus (Gillies, 1951) [southern India], Thraulus thraker Jacob, 1988 [ Bulgaria] cannot be assigned to a subgenus because their nymphs are still unknown.

Figures

Figure 12. Thraulus (Thraulus) noe sp. nov. 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 18. Thraulus (Thraulus) wemale sp. nov. 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 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 29. Thraulus (Masharikella) pascalae sp. nov. 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).