Papuanatula (Papuanatula) obscurella 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 obscurella

description: Papuanatula (Papuanatula) obscurella sp. nov.
Figs 72, 73, 74, 75, 76
Etymology.
The species name obscurella refers to the dark color of male imago (Fig. 75 d).
Material examined.
Holotype. L-S-I ♂ {specimen number [VIII (5) B 2012}; Indonesia • Papua, Baliem valley, Wamena, river Elagaima; 19. viii. 2012; coll. N. Kluge & L. Sheyko; SPbU. Paratypes. same locality and collectors, 15–19. viii. 2012: 2 L-S ♂, 1 L-S-I ♀, 17 larvae; SPbU.
Diagnosis.
Larva. The following combination of characters distinguishes P. obscurella sp. nov. from other species of Papuanatula s. str.: body without long, fine, simple setae along midline; abdominal terga without protuberances; femur without hypodermal pigmentation; abdominal terga with pointed denticles on posterior margins; tergalii with non-pigmented tracheae; abdomen with hypodermal coloration (brown band on posterior margins of terga I – IX); turbinate eyes with diminished facetted surfaces.
Description.
Larva (Figs 72 – 74). Cuticular coloration. Head, pronotum, mesonotum and metanotum brownish, with darker and paler areas; fore protoptera nearly uniformly brownish (Fig. 72 a, e, f). Thoracic pleura brownish, sterna mostly colorless. Cuticle of femur with wedge-shape colorless blank on proximal 1 / 2 and colorless blank occupying most part of distal 1 / 2; other surface of femur brownish, apex bordered with darker brown (Fig. 72 b – d). Tibia and tarsus from colorless to pale brownish (Fig. 72 b – d). Abdominal terga mostly brownish, with lateral areas paler; terga V – VI more or less paler than others; sterna mostly colorless (Fig. 72 a). Cerci uniformly pale brownish.
Hypodermal coloration. Legs without hypodermal markings. Hypodermal coloration of abdomen either non-expressed or represented by dark brown transverse band close to posterior margin of each tergum I – IX, sometime with other brown markings on abdominal terga (Fig. 72 h, i). Tissues of tergalii colorless, without pigmentation associated with trachea, so tracheae poorly visible (Fig. 72 g – i).
Head. Antenna (Fig. 72 e). Length ~ 2 × head length. As typical for subgenus. Developing turbinate eyes of last instar male larva (Fig. 72 e) with larger facets in middle and smaller facets on periphery. Labrum (Fig. 73 e) widened distally; long setae on dorsal surface numerous and forming integral, regular transverse row; each seta consists of stout stem and numerous long processes on both sides. Right mandible (Fig. 73 b, d). As typical for subgenus. Left mandible (Fig. 73 a, c). As typical for subgenus. Hypopharynx (Fig. 73 f). As typical for genus. Maxilla. (Fig. 73 h). Maxillary palp as long as galea-lacinia. Otherwise, as typical for genus. Labium. (Fig. 73 g) Paraglossae widened near middle, with lateral side forming concavity in proximal part; three apical setal rows sharply 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.
Thorax. Sterna. Without protuberances. Terga without protuberances; without long, fine setae on midline. Metanotum without hind protoptera or their vestiges. Legs (Figs 72 b – d, 74 a, b). Fore femur slightly widened in proximal part; hind tibia shorter than others. Femur. Outer side of each femur with single regular row of long, hair-like setae bearing numerous fine, short branches on all sides (as in Figs 41 g, 68 b). 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 setae similar to that on femur. Tarsus. Anterior side of each tarsus with regular row of similar, but smaller (shorter and narrower) setae. Posterior side of each tarsus with regular row of short, stout, oval setae (looking pointed in profile) and one much longer, thinner, pointed seta distad of them. Claw with row of four or five short denticles and one somewhat larger denticle distad of them; long, arched posterior seta.
Abdomen. Terga (Figs 72 a, 74 c) without dorsal unpaired or paired protuberances, only with slightly expressed, unpaired, median elevations; without long, fine setae on midline. Abdominal terga and sterna without scales. Posterior margins of abdominal terga I – IX with short denticles, short and blunt on several anterior terga, longer and pointed on several posterior terga. Posterior margin of tergum X with very small denticles. Tergalii (Fig. 72 a, g – i) of abdominal segment I absent; tergalii II – VII subequal. Each tergalius with costal and anal ribs narrow, smooth, present on proximal 1 / 2 of tergalius only (as in Fig. 66 i). Paraprocts (Fig. 74 d) without posterior projection; margins membranous, smooth, lacking denticles. Caudalii (Fig. 72 a) without swimming setae or their vestiges. Paracercus short, consisting of ~ 6–8 segments.
Pose of subimaginal gonostyli under larval cuticle (Fig. 76 b). In mature larva ready to molt to subimago, subimaginal gonostyli packed under larval cuticle in “ Labiobaetis - type ” pose: 2 nd segments 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 (as in Fig. 60 f). Mesonotum pale brown with medioparapsidal suture colorless, other sutures darker brown (Fig. 75 g). Meso- and metathoracic pleura and sterna with colorless, pale brownish and dark brown areas (Fig. 75 h). Cuticle of wings colorless, with microtrichiae brownish. Legs nearly colorless, with pale brown bordering on femur and base of tibia (as in Fig. 36 d). Abdomen diffusely colored with very pale brownish, mostly in distal part. Cerci colorless with setae brown.
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 (Fig. 75 c – f). Head dark brown. Antennae with scape ochre, pedicel brown, flagellum ochre. Turbinate eyes dark brown, high and narrow, cylindrical, with faceted surfaces round and widely separated. Thorax brown, equally dark dorsally, laterally, and ventrally. Fore wing with membrane colorless, veins ochre. Pterostigma with three or four incomplete, oblique cross veins (Fig. 75 f). Legs ochre (Fig. 75 i, j). Abdominal terga brown, each tergum I – IX with darker brown transverse band close to posterior margin; sterna slightly paler, ochre-brown (Fig. 75 c – e). Cerci brown.
Genitalia (Fig. 76 a): Sterno-styligeral muscle absent. Each unistyliger parallel-sided, equally wide at base and at apex. At lateral side of gonostylus, its 1 st segment roundly-convex at apex and separated from 2 nd segment by concavity; at median side of gonostylus, 1 st segment gradually turns to 2 nd segment. Second segment equally wide all over its length. 3 rd (terminal) segment of gonostylus nearly as wide as 2 nd, with length slightly exceeding width. Penial bridge with truncated trapezoid projection between unistyligers. Gonovectes dark brown. Each gonovectis parabolic, with lateral (basal) and median (apical) portions equally long, apex slightly bent medially.
Imago, female (Fig. 75 a, b). Head and thorax dorsally ochre-brown, ventrally mostly ochre. Abdomen mostly ochre, each tergum I – IX with dark brown transverse band close to posterior margin. Coloration of legs, wings, and cerci as in male.
Egg (Fig. 37 c). Irregularly oval. Chorion without regular relief.
Dimension.
Fore wing length (and approximate body length): male 4.5 mm, female 6 mm.
Comparison.
Larva of P. obscurella sp. nov. resembles P. plana by absence of hypodemal pigmentation on femora, absence of tubercles and long setae on abdominal terga, pointed denticles on posterior margins of abdominal terga and non-pigmented tracheae of tergalii. At the same time, male larva and male imago of P. obscurella sp. nov. differ from P. plana by abdominal hypodermal coloration (which is represented by brown band equally developed on posterior margins of each tergum I – IX in P. obscurella sp. nov. vs brown spot on tergum IV in P. plana) and by shape of turbinate eyes (with diminished faceted surfaces in P. obscurella sp. nov. vs wide faceted surfaces in P. plana).
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