Papuanatula (Papuanatula) balkei Kaltenbach, Kluge & Gattolliat, 2025, sp. nov.
Creators: name: Kaltenbach, Thomas
name: Kluge, Nikita J.
name: Gattolliat, Jean-Luc
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Baetidae
Papuanatula
Papuanatula balkei

description: Papuanatula (Papuanatula) balkei sp. nov.
Figs 26, 27, 28, 29, 30, 31
Etymology.
The species is dedicated to Michael Balke (ZSM / SNSB), the collector of an important part of the material used in this study.
Material examined.
Holotype. Papua New Guinea • larva; Eastern Highlands Prov., Marawaka, Ande; near 07°01'42"S, 145°49'48"E; 1700–1800 m, 9. xi. 2006, leg. M. Balke & Kinibel; (PNG 87); on slide; GBIFCH 00592545, GBIFCH 00592547; ZSM / SNSB. Paratypes. 20 larvae; same data as holotype; 5 on slides; GBIFCH 00592544, GBIFCH 00592546, GBIFCH 00592626, GBIFCH 00975797, GBIFCH 00975798, GBIFCH 00976040; MZL; 15 in alcohol; GBIFCH 00975770, GBIFCH 00976050, GBIFCH 00976108, GBIFCH 00976141; MZL.
Other material.
Papua New Guinea • 26 larvae; Western Highlands Prov., Simbai; 05°16'20"S, 144°33'11"E; 1800–2000 m; 25. ii. 2007; leg. Kinibel; (PNG 133); 2 on slides; GBIFCH 00976049, GBIFCH 00976095; MZL; 24 in alcohol; GBIFCH 00975786, GBIFCH 00976043, GBIFCH 00976096, GBIFCH 00976097; MZL.
Diagnosis.
Larva. The following combination of characters distinguishes P. balkei sp. nov. from other species of Papuanatula s. str.: body dorsally with irregular row of long, fine, simple setae along midline; abdominal terga without protuberances; femur proximally with wedge-shaped blank, overlaid with scattered brown color; abdominal terga brown, laterally darker, terga V, VI, and X brighter; tergalii with pigmented tracheation; paracercus with seven or eight segments; abdominal terga with triangular, apically rounded denticles on posterior margin; small scattered scales on abdominal terga elongate, slightly trapezoid.
Description.
Larva (Figs 26 – 31). Body length 4.2–5.6 mm, cerci much longer than body length (~ 1.5 ×).
Cuticular coloration (Fig. 26 a – c). Head, thorax and abdomen dorsally brown; thorax with complex pattern; abdominal segments laterally darker, V, VI, and X brighter. Femur proximally with wedge-shaped blank, overlaid with scattered brown color; medial area grey-brown, distal area yellow-brown to grey-brown; tibia grey; tarsus grey, distally brown. Head, thorax and abdominal segment I ventrally ecru, protuberances of thoracic sterna brown; abdominal segments II – X ventrally pale brown, darker toward end of abdomen. Cerci grey-brown.
Hypodermal coloration. Each abdominal tergum I – IX with wide dark brown transverse band close to anterior margin and with narrower dark brown transverse band close to posterior margin (Fig. 26 a).
Head (Figs 26 b, 29 h). Dorsally with irregular row of long, fine, simple setae along midline. Antenna. Length ~ 1.5 × head length. Otherwise, as typical for subgenus. Developing turbinate eyes in last instar male larva (Fig. 29 h) ovoid, with large distance to each other. Labrum (Fig. 27 a, b). Length 0.5 × maximum width, laterally convex. Dorsal, sub-marginal arc with 24–29 feathered setae. Right mandible (Fig. 27 d, e). Margin between prostheca and mola with row of minute denticles. Otherwise, as typical for subgenus. Left mandible (Fig. 27 f, g). Margin between prostheca and mola with row of minute denticles. Otherwise, as typical for subgenus. Hypopharynx (Fig. 27 c). As typical genus. Maxilla (Fig. 28 c, d). Maxillary palp subequal in length to galea-lacinia; palp segment II slightly longer than segment I. Otherwise, as typical for genus. Labium (Fig. 28 a, b). As typical for genus. Paraglossa dorsally with two spine-like setae near inner, distolateral margin. Labial palp with segment I subequal in length to segments II and III combined. Segment II with minute distomedial protuberance, dorsally with row of four spine-like setae near outer, distolateral margin. Segment III slightly pentagonal, pointed; 0.7 × length of segment II; inner dorsal margin with few feathered setae.
Thorax. Sterna. With small protuberances on sides of prosternum and close to openings of mesothoracic and metathoracic sternal apodemes (as in Fig. 108 a). Terga (Fig. 26 b) without protuberances; with irregular row of long, fine, simple setae along midline. Metanotum without hind protoptera or their vestiges. Legs (Fig. 29 a – g). Ratio of leg segments: fore leg 0.8: 1.0: 0.4: 0.1, middle leg 0.9: 1.0: 0.3: 0.1 and hind leg 1.0: 1.0: 0.4: 0.2. Femur. Length ~ 3.7 × maximum width. Claw with one row of 5–7 denticles and one or sometimes two posterior setae.
Abdomen. Terga (Figs 30 a, 31 a – c) with irregular row of long, fine, simple setae along midline. Terga without protuberances, terga I – IV with slight, paired medioposterior elevations. Posterior margin of terga: I with rudimentary denticles, II – IX with triangular, apically rounded denticles. Surface with scattered small, elongate, slightly trapezoid, striated scales. Tergalii (Fig. 30 d, e). Broad ovoid, tracheation well pigmented; margins smooth, with few short, fine, simple setae. Paraproct (Fig. 30 f). Posterior margin with prolongation and row of minute denticles. Caudalii (Fig. 30 b, c). Cerci apart from basal and distal part with 1–7 swimming setae per segment, initially increasing and then again decreasing toward distal part. Paracercus with seven or eight segments.
Pose of subimaginal gonostyli under larval cuticle. Unknown.
Subimago. Unknown.
Imago. Unknown.
Egg. Unknown.
Distribution.
New Guinea (Fig. 146).
description: Published as part of Kaltenbach, Thomas, Kluge, Nikita J. & Gattolliat, Jean-Luc, 2025, Redescription of Papuanatula Lugo-Ortiz & McCafferty (Ephemeroptera, Baetidae), with description of a new subgenus and 20 new species, pp. 159-347 in ZooKeys 1227 on pages 159-347, DOI: 10.3897/zookeys.1227.138100