Thraulus (Thraulus) timorensis Sartori & Salles, 2025, sp. nov.

Thraulus (Thraulus) timorensis sp. nov. Figs 16, 17, 34 E Material examined. Holotype. • Indonesia, Timor, nymph on slide, GBIFCH 01223095, some gills in ethanol, GBIFCH 01523478, Naikliu area, restpools in dry forest, 130 m, 03.X.2011, 09°58.425'S, 123°41.439'E, M. Balke col [TIM 11] (MZB). Nymph. Body length, female: 6.5 mm. Diagnosis. Labrum cordiform, medial emargination shallow without denticles; dorsal face of labrum with multiple rows in distal position; tarsal claw hooked with 15 teeth and a palisade of four other teeth in distal position; gill lamellae on segments II – VI with> 25 filaments each; posterolateral projections of the abdomen present on segments VIII and IX. Colouration. Femur, tibia, and tarsi whitish. Description. Head. Labrum cordiform (Fig. 16 A). Ratio labrum width / clypeus width 0.95. Ratio labrum width / insertion width 1.39. Medial emargination shallow without denticles. Proximal row of setae present, simple. Number of setae on proximal row ~ 29. Distal row of setae multiple (Fig. 16 C). Median part of labrum in ventral view with stout setae in a row (Fig. 16 B). Mandibles. Outer margin with middle tuft of setae. Right mandible with ten setae below mola (Fig. 16 D). Maxillae. Posterior margin of cardo broken. Proximo-lateral margin of stipes with single long stout seta (Fig. 34 E). Apical-ventral row with 22 pectinate setae. Maxillary palp segment II 0.82 as long as segment I. Maxillary palp segment III 0.78 as long as segment I (Fig. 16 E). Stout setae on outer margin of segment I absent. Segment II inner margin with five stout setae, outer margin without stout setae. Segment III inner margin with five stout setae, dorsal surface with few setae at apex. Segment III 1.67 × as long as base width. Labium. Labial palp segment II 0.76 as long as segment I. Labial palp segment III 0.76 as long as segment I (Fig. 16 F). Segment I inner margin with two stout setae, outer margin with 12 stout setae. Segment II outer margin with ten stout setae. Segment III dorsal face with five stout setae. Segment III 2.90 × as long as base width. Hypopharynx. Apex of superlingua truncate (Fig. 16 F). Thorax. Dorsal margin of femur with a row of long, stout and pointed setae; regular submarginal row with setae as long as those of dorsal margin (Fig. 17 A); ventral margin with short and pointed setae and a submarginal row of short and blunt but stout setae, except on hind leg where those on ventral margin are short and blunt (Fig. 17 B); central area of upper surface with few long pointed setae. Middle tibia with two rows of long pointed setae on ventral margin, outer margin with few hair-like setae; hind tibia with a row of long thin setae on ventral margin, upper and lower surfaces covered with simple and some feathered setae, outer margin with long and short pointed stout setae. Tarsal claw hooked with 15 denticles, together with a palisade of four small denticles at apex (Fig. 17 C). Abdomen. Gill I with single bifid lamella. Gills II – VII with dorsal and ventral lamellae, dorsal lamella smaller. Gills II – VI with upper lamella entirely bordered with ~ 35 very long filaments, lower lamella with ~ 30 very long filaments (Fig. 17 D); gill VII smaller but with the same number of long filaments. Posterior margin of terga IX with denticles. Posterior margin of terga VIII with minute denticles. Posterior margin of terga V – VII without denticles. Posterolateral projections present on segments VIII – IX. Derivatio nominis. This species is named after the island from where it comes. Although we have a single nymph in hand, we think important to formally named it, since it possesses distinct characters; moreover, it is the first Leptophlebiidae described from this island and only the second mayfly species (Kaltenbach and Gattolliat 2017).