Thraulus (Thraulus) ogea, 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.15923145
persistent identifier	https://treatment.plazi.org/id/820127E1-D2DE-59DE-99F2-15EE7EBEADB7
treatment provided by	ZooKeys by Pensoft
scientific name	Thraulus (Thraulus) ogea
status	sp. nov.

Treatment

Thraulus (Thraulus) ogea sp. nov.

Figs 11 B View Figure 11 , 14 View Figure 14 , 15 View Figure 15 , 20 B – D View Figure 20

Material examined.

Holotype. • Papua New Guinea, nymph on slide, Madang Province, Trans Gogol , 30 m, II.2008, 5°18.0915'S, 145°36.4532'E, BRC col [PNG 179], GBIFCH 01223108 ( ZSM) GoogleMaps . Paratypes. • Papua New Guinea, 4 nymphs in ethanol ( UFVB), 22 nymphs in ethanol, GBIFCH 01513476 , 2 nymphs entirely mounted on slides, GBIFCH 01223107 , GBIFCH 01223106 , same data as holotype ( MZL) GoogleMaps .

Nymph.

Body length, male: 3.6–3.9 mm Body length, female: 4.2–4.4 mm.

Diagnosis.

Labrum cordiform, medial emargination shallow with flat denticles; median part of labrum in ventral view with stout setae in a row; outer margin of mandibles with tuft of setae in medium and distal positions; posterior margin of cardo with few hair-like setae; gill lamellae on segments II – VI without filaments on basal half, with <20 filaments on each; posterolateral projections of the abdomen present on segments VII – IX.

Colouration.

Head. Pale brown, greyish brown between ocelli and eyes. Antenna whitish. lower portion black, upper portion reddish brown, outer ommatidia dark brown. Mouth parts: clypeus greyish brown. Thorax. Pronotum greyish brown, with two pale brown markings medially. Mesonotum greyish brown, washed with dark brown laterally and medially (Fig. 11 B View Figure 11 ). Metanotum greyish brown. Femur yellowish brown, with one pale brown marking in the middle and one distally. Tibia uniformly yellowish. Tarsi uniformly yellowish. Abdomen. Terga medium brown, posterior margin dark brown. Sterna yellowish grey. Gills purplish brown. Terminal filaments uniformly yellowish white.

Description.

Head. Labrum cordiform (Fig. 14 A View Figure 14 ). Ratio labrum width / clypeus width 0.93–0.94. Ratio labrum width / insertion width 1.29–1.30. Medial emargination shallow with flat denticles. Proximal row of setae present, simple. Number of setae on proximal row 35–47. Distal row of setae present, simple. Median part of labrum in ventral view with only scattered stout setae (Fig. 14 B View Figure 14 ). Mandibles. Outer margin with middle tuft of setae, and with distal tuft of setae. Right mandible with nine or ten setae below the mola (Fig. 14 C View Figure 14 ). Maxillae. Posterior margin of cardo with few hair-like setae. Proximo-lateral margin of stipes with a single stout and medium-sized seta. Apical-ventral row with 25–29 pectinate setae. Maxillary palp segment II 0.77–1.05 as long as segment I. Maxillary palp segment III 0.69–0.73 as long as segment I (Fig. 14 D View Figure 14 ). Stout setae on outer margin of segment I absent. Segment II inner margin with five stout setae, outer margin with five or six stout setae. Segment III inner margin with three stout setae, dorsal surface with few setae at apex. Segment III 1.89–2.57 × as long as base width. Labium. Labial palp segment II 0.81–0.82 as long as segment I. Labial palp segment III 0.71–0.81 as long as segment I (Fig. 14 E View Figure 14 ). Segment I inner margin with 8–11 stout setae, outer margin with 12 or 13 stout setae. Segment II outer margin with four or five stout setae. Segment III, dorsal face with three or four stout setae. Segment III 3.0–3.57 as long as base width. Hypopharynx. Apex of superlingua truncate (Fig. 14 F View Figure 14 ).

Thorax. Dorsal margin of femur with a row of stout and long setae, and a submarginal row with same setae; ventral margin with shorter and stouter setae; upper surface with few long and pointed stout setae (Fig. 15 A View Figure 15 ). Tarsal claw hooked with 4–6 denticles progressively larger apically.

Abdomen. Gill I with single bifid lamella. Gills II – VII with dorsal and ventral lamellae, dorsal lamella smaller. Gill II to VI with seven to ten filaments on upper lamella and 12–14 on the ventral one, filamentous projections lacking on proximal half; gill VII with three or four filaments on each lamella. Posterior margin of terga IX with denticles. Posterior margin of terga IX with denticles (Fig. 15 B View Figure 15 ). Posterior margin of terga VIII with minute denticles. Posterior margin of terga V – VII without denticles. Posterolateral projections present on segments VII – IX.

Eggs. General shape elongated. Size 190 μm × 75 μm. Chorionic surface smooth and uplifted compared to attachment structures (Fig. 20 B View Figure 20 ). Attachment structures composed of nine long slender filaments attached to each pole (Fig. 20 C View Figure 20 ); presence of two transverse filaments at the micropyle opening (Fig. 20 D View Figure 20 ). Micropyle in equatorial position.

Derivatio nominis.

This species is named after the ethnic group Ogea, who live close to the Gogol River, and is a noun in apposition.