Papuanatula (Papuanatula) bessa Lugo-Ortiz & McCafferty 1999
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 bessa

description: Papuanatula (Papuanatula) bessa Lugo-Ortiz & McCafferty, 1999
Figs 1, 2, 3, 4, 5, 6
Papuanatula bessa Lugo-Ortis & McCafferty, 1999: 63 (larva, ♂ and ♀ subimago).
Material examined.
Type locality (‘ additional material’ of original description). Papua New Guinea • 15 larvae; Morobe Prov., E of Wau, Bulolo Riv.; 900 m; 18. x. 1964; leg. WL and WG Peters; 3 on slides; GBIFCH 00592634, GBIFCH 00976069, GBIFCH 01221771; MZL; 12 in alcohol; GBIFCH 00976073, GBIFCH 00975821; MZL.
Other material.
Papua New Guinea • 6 larvae; Gulf Prov., Marawaka, Mala; 07°05'40"S, 145°44'28"E; 1400 m; 11. xi. 2006; leg. M. Balke & Kinibel; (PNG 90); 1 on slide; GBIFCH 00976130; MZL; 5 in alcohol; GBIFCH 00975772, GBIFCH 00976022, GBIFCH 00976129, GBIFCH 00976131; MZL • 8 larvae; Morobe Prov., Menyamya, Mt Inji; near 07°14'49"S, 146°01'20"E; 1700 m; 14. xi. 2006; leg. M. Balke & Kinibel; (PNG 96); in alcohol; GBIFCH 00975779, GBIFCH 00976085; MZL • 2 larvae; Central Prov., Tapini; 08°20'31"S, 146°59'49"E; 870 m; 29. x. 2007; leg. Kinibel; (PNG 161); in alcohol; GBIFCH 00975785, GBIFCH 00976094; MZL • 9 larvae; Morobe Prov., Wagau, Herzog Mts; 06°51'04"S, 146°48'04"E; 1150 m; 19. xi. 2006; leg. M. Balke & Kinibel; (PNG 102); 1 on slide; GBIFCH 00592633; MZL; 8 in alcohol; GBIFCH 00975777, GBIFCH 00976081, GBIFCH 00976082, GBIFCH 00976083; MZL. INDONESIA • Papua, Waena; 8–13. viii. 2012; coll. N. Kluge & L. Sheyko: 3 L-S ♂, 13 larvae; SPbU.
Diagnosis.
Larva. The following combination of characters distinguishes P. bessa from other species of Papuanatula s. str.: body dorsally with irregular row of long, fine, simple setae along midline; metanotum and abdominal terga I – V with medioposterior, broad, paired humps; abdominal terga II – IV dark brown, with brighter oblong markings; tergum V yellow brown with T-shaped dark brown marking (Fig. 1 a; Lugo-Ortiz and McCafferty 1999: fig. 5); femur brownish, with wedge-shaped blank in proximal 1 / 2; paracercus with eight segments.
Description.
Larva (Figs 1 a – 5 h). Body length 3.8–4.9 mm, cerci much longer than body length (~ 1.5 ×).
Cuticular coloration. Head, pronotum, mesonotum, and metanotum brownish, with darker and paler areas; fore protoptera with narrow paler lines corresponding to all longitudinal and intercalary veins (Fig. 2 c). Thoracic pleura brownish, sterna with brownish and colorless areas. Cuticle of femur with wedge-shape colorless blank on proximal 1 / 2 and less distinct blank occupying most part of distal 1 / 2; other surface of femur brownish, apex bordered with darker brown (Figs 2 d – f, 4 a). Tibia and tarsus brownish (Fig. 2 d – f). Abdominal terga mostly brownish, with lateral areas paler; terga V – VI more or less paler than others; sterna mostly colorless (Figs 1 a, 2 g). Cerci uniformly pale brownish.
Hypodermal coloration. Legs without hypodermal markings. Abdominal terga with extensive, contrasting, dark brown markings of characteristic shape (Figs 1 a, 2 a). Tissues surrounding tracheae of tergalii partly with brown pigmentation.
Head. Dorsally with row of long, fine, simple setae along midline (as in Figs 26 b, 65 b). Antenna (Fig. 2 a, b). Length ~ 1.5 × head length; otherwise, typical for subgenus. Developing turbinate eyes in last instar male larva. With larger facets in middle and smaller facets on periphery (as in Fig. 66 h). Labrum (Fig. 3 a, b) Length 0.5 × maximum width, laterally convex; widened distally; 30–35 long, feathered setae on dorsal surface forming integral, regular transverse row; each seta consists of stout stem and numerous long processes on both sides. Right mandible (Fig. 3 e). Incisor sharply pointed, with two denticles near base. Kinetodontium terminated with three denticles, with distal denticle longest. Otherwise, as typical for subgenus. Left mandible (Fig. 3 f). Incisor sharply pointed, with two denticles near base. Kinetodontium terminated with three denticles, with distal denticle longest. Otherwise, as typical for subgenus. Hypopharynx (Fig. 3 d). As typical for genus. Maxilla (Fig. 3 g). Maxillary palp as long as galea-lacinia. Otherwise, as typical for genus. Labium (Fig. 3 c). Paraglossae widened near middle, with lateral side forming concavity in proximal part; three apical setal rows sharply bent. Glossa as long as 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 longer than lateral margin.
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 with irregular row of long, fine, soft, colorless, simple setae along midline (as in Figs 26 b, 65 b). Metanotum with medioposterior broad, paired elevations. Metanotum without hind protoptera or their vestiges. Legs (Figs 2 d – f, 4 a – e). Fore femur slightly widened in proximal part; hind tibia shorter than others. Ratio of leg segments: fore leg 0.8: 1.0: 0.3: 0.2, middle leg 0.9: 1.0: 0.3: 0.2 and hind leg 1.0: 1.0: 0.3: 0.2. Femur. Length ~ 4 × maximum width. 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 (originally located on outer side) turned to anterior side. Anterior (originally outer-anterior) side of each tibia with regular row of setae similar to that on femur. Tarsus. Anterior (originally outer) side of each tarsus with regular row of similar, but smaller (shorter and narrower) setae. Posterior (originally inner) 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 six or seven short denticles and one somewhat larger denticle distad of them; long, arched posterior seta on posterior side near distal denticle.
Abdomen. Terga (Fig. 5 a – g). Long, fine, soft, colorless setae irregularly situated along midline of all abdominal terga (as in Figs 26 b, 65 b). Each abdominal tergum with pair of submedian protuberances, more prominent on terga I – IV and less prominent to absent on more posterior terga; each protuberance with compact group of short, blunt, parallel-sided, colorless scales with round sockets. Other surface with fewer, sparse scales of such kind. Posterior margins of abdominal terga partly without denticles, partly with short, blunt denticles separated by spaces. Tergalii (Figs 2 g, 4 f, g) of abdominal segment I absent; tergalii II – VII subequal, oval. Each tergalius with costal and anal ribs narrow, present on proximal part of tergalius only. Tracheation poorly developed or absent; margins smooth, with short, fine, simple setae. Paraproct (Fig. 5 h) with posterior prolongation bent toward bases of caudalii, with many small, equal denticles on median-posterior margin. Caudalii (Fig. 4 h, i) without swimming setae; vestiges of swimming setae present on distal part of cerci. Paracercus short, consisting of ~ 7–10 segments.
Pose of subimaginal gonostyli under larval cuticle. 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 (Fig. 6 d).
Subimago. 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. Unknown. Following features can be revealed based on subimaginal structure: Turbinate eyes narrow and cylindrical, with stem reddish and faceted surface small, round, black. Legs ochre, without brown hypodermal markings. Abdomen with characteristic hypodermal coloration forming brown and ochre areas (Fig. 6 a – c).
Imago, female. Unknown. Judging by description of subimago (Lugo-Ortiz and McCafferty 1999: 64), hypodermal coloration of abdominal terga as in male.
Egg. Unknown.
Dimension.
Fore wing length (and approximate body length): 4 mm.
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