Papuanatula (Papuanatula) heterochaeta 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 heterochaeta

description: Papuanatula (Papuanatula) heterochaeta sp. nov.
Figs 55, 56, 57, 58, 59, 60, 61
Etymology.
The species name heterochaeta refers to the sharp difference between blunt-ended setae which form the longitudinal row on outer side of larval femur and small hair-like setae which form continuation of this row on apex of the femur (Fig. 58 a).
Material examined.
Holotype. L-S-I ♂ {specimen number [XX] (5) A 2012} Indonesia • Papua, Depapre; 28. viii. 2012; coll. N. Kluge & L. Sheyko; SPbU. Paratypes. Same data as holotype; S-I ♂ (reared together with holotype, larval exuviae lost); same data as holotype; 25–28. viii. 2012; 1 S-I ♂, 10 larvae. Indonesia • Waena; 8–13. viii. 2012; coll. N. Kluge & L. Sheyko; 2 L-S ♀, S / I ♂, 6 larvae. All material in SPbU.
Diagnosis.
Larva. The following combination of characters distinguishes P. heterochaeta sp. nov. from other species of Papuanatula s. str.: body dorsally without irregular row of long, fine, simple setae along midline; abdominal terga without protuberances; hypopharynx apically with pair of bunches of setae-like spines (instead of one bunch as usually); femur with large, proximal, oval blank and with dark brown, shoe-shaped macula inside proximal blank; sharp difference between setae which form the longitudinal row on outer side of femur and setae which form continuation of this row on apex of femur; long, slender, preapical seta on tarsus absent; paracercus with ~ 10–12 segments.
Description.
Larva (Figs 55 – 59). Cuticular coloration. Head, pronotum, mesonotum and metanotum brownish with paler areas; fore protoptera with narrow paler lines corresponding to some longitudinal veins (Fig. 56 a, b). Thoracic pleura brownish, sterna mostly colorless. Cuticle of femur with brownish margins and brownish transverse band separating large proximal blank from smaller distal blank; proximal blank oval (not wedge-shaped), occupying most part of proximal 1 / 2 (Fig. 56 d – f). Tibia and tarsus mostly brownish (Fig. 56 d – f). Abdominal terga brownish with paler blanks; median blank on tergum VI larger than others. Sterna mostly colorless (Fig. 56 c). Cerci uniformly pale brownish.
Hypodermal coloration. Anterior side of each femur with dark brown shoe-shaped macula on proximal 1 / 2, within proximal cuticular blank (Fig. 55 f, g); posterior side of each femur with or without two longitudinal, brown maculae (Fig. 55 d), sometimes connected one with another (Fig. 55 b). Boundaries between abdominal terga narrowly bordered by dark brown; other brown markings on abdomen absent or present, most extensive on abdominal tergum IV (Fig. 55 a). Tissues surrounding tracheae of tergalii (main trachea and its branches) with brown pigmentation (Fig. 59 d – i).
Head. Antenna. As typical for subgenus. Developing turbinate eyes in last instar male larva with facets equally developed on middle and peripheric areas (as in Fig. 32 d). Labrum (Fig. 57 a, b) very slightly widened distally; long setae on dorsal surface spaced and forming regular transverse row; each seta pointed, with moderately long processes on both sides. Right mandible (Fig. 57 d, f). As typical for subgenus. Left mandible (Fig. 57 c, e). Incisor and kinetodontium non-distinguishable, together with 5 denticles proximad of stretched apex of incisor. Otherwise, as typical for subgenus. Hypopharynx (Fig. 57 j) apically with pair of bunches of stout setae-like spines. Maxilla (Fig. 57 g). Maxillary palps long as galea-lacinia. Otherwise, as typical for genus. Labium (Fig. 57 h, i). Paraglossae widest at base and narrowing toward apex; three apical setal rows bent at apex of paraglossa. Glossa shorter than half of paraglossa, with finger-like (distal) portion as long as triangular (proximal) portion. Glossa with several long setae at apex and one long seta near middle of ventral side. Labial palp without distomedian projection on segment II; segment III with median margin as long as lateral margin.
Thorax. Sterna without protuberances. Terga. Without long setae along midline. Metanotum without hind protoptera or their vestiges. Legs (Figs 56 d – f, 58 a – f). Fore femur widened in proximal part; hind tibia shorter than others. Femur. Outer side of each femur with single regular row of long setae; each seta slender, flattened, narrowing toward apex and blunt apically, with numerous fine, short branches on all sides. Distally, close to femur-tibia articulation, setal row continued by several smaller, hair-like setae (similar to setae on tibia). Anterior side of femur with small, stout setae, sparsely and irregularly situated. Serrate area located at middle of anterior side, partly on brown transverse band, partly on proximal blank. Tibia. Patella-tibial suture present on all legs, terminated near middle of inner margin of tibia. Tibia-tarsal condylus turned to anterior side. Anterior side of each tibia with regular row of hair-like setae similar to setae near apex of femur. Tarsus. Anterior side of each tarsus with regular row of similar, but shorter (not narrower) setae. Long preapical seta absent; posterior side of each tarsus with regular row of few very short, stout setae and one longer, pointed seta of same thickness distad of them (Fig. 58 b, c). Claw with row of 6–9 denticles and one somewhat larger denticle distad of them; long, arched, posterior seta (Fig. 58 e, f).
Abdomen. Terga (Figs 56 c, 59 a, b) without dorsal protuberances, only with slightly expressed, unpaired, median elevations; without long setae along midline. Abdominal terga with numerous small scales with small sockets and fan-like striation. Abdominal terga I – III without denticles on posterior margins; posterior margins of abdominal terga IV – IX with small, pointed denticles. Posterior margin of tergum X with very small denticles. Tergalii (Fig. 59 d – i) of abdominal segment I absent; tergalii II – VII subequal, oval, relatively narrow. Each tergalius with costal and anal ribs narrow, smooth, present on proximal 1 / 2 of tergalius only. Paraproct (Fig. 59 c). Margins membranous and smooth, lacking denticles. Caudalii (Fig. 59 c) without swimming setae or their vestiges. Paracercus short, consisting of ~ 10–12 segments.
Pose of subimaginal gonostyli under larval cuticle (Fig. 61 a). In mature larva ready to molt to subimago, subimaginal gonostyli packed under larval cuticle in “ Labiobaetis - type ” pose, as typical for the genus. 2 nd segment directed medially and bent proximally; 3 rd segment directed medially (as continuation of 2 nd segment) and narrowed apically, being deformed corresponding to space between subimaginal styliger and larval cuticle.
Subimago. Cuticular coloration. Pronotum and prosternum partly brown (Fig. 60 f). Mesonotum pale brown with medioparapsidal suture colorless, other sutures darker brown (Fig. 60 e). Meso- and metathoracic pleura and sterna with colorless, pale brownish and dark brown areas (Fig. 60 f). Cuticle of wings colorless, with microtrichiae brownish. Legs nearly colorless, with pale brown bordering on femur and base of tibia (Fig. 60 d). Abdomen very pale brownish with colorless sigilla. Cerci colorless with setae brownish.
Hypodermal coloration. As in imago.
Texture. On all legs of both sexes, each tarsomere covered mostly with blunt microlepides, with pointed microlepides near apex (as in Fig. 70 i).
Imago. Imago, male. Head ochre. Antennae ochre. Turbinate eyes red, widened apically. Thorax ochre, equally pale dorsally, laterally, and ventrally, with dark brown hypodermal markings on lateral sides. Fore wing with membrane colorless, veins ochre. Pterostigma with three or four incomplete, oblique cross veins (Fig. 60 a – c). Legs mostly ochre; on leg of each pair, anterior side of femur with contrasting, dark brown, longitudinal macula just proximad of midlength; posterior side of femur with reddish brown macula near apex (Fig. 60 g). Abdomen mostly whitish or ochre; each tergum I – IX with dark brown transverse band close to posterior margin; each tergum III and IV with pair of brown spots; tergum IV with transverse brown macula posteriad-mediad of them (Fig. 60 a – c). Cerci ochre.
Genitalia (Fig. 61 c, d). Sterno-styligeral muscle absent. Each unistyliger sharply widened apically on median side, so that median margins convergent distally. 1 st segment of gonostylus with lateral side convex, median side median side gradually turns to 2 nd segment. Second segment equally wide all over its length. Third (terminal) segment of gonostylus nearly as wide as 2 nd, with length slightly exceeding width. Penial bridge with wide, blunt, membranous projection between unistyligers. Each gonovectis parabolic, with lateral (basal) and median (apical) portions equally long, apex bent medially-caudally.
Imago, female (Fig. 60 d). Unknown. Judging by subimago, coloration of head, thorax, and legs similar to that of male; abdominal terga with ochre-brown pigmentation.
Egg. Unknown.
Dimension.
Fore wing length (and approximate body length) 4–5 mm.
Distribution.
New Guinea (Fig. 147).
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