Papuanatula Lugo-Ortiz & McCafferty, 1999

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, ZooKeys 1227, pp. 159-347 : 159-347

Papuanatula Lugo-Ortiz & McCafferty, 1999

Type species.

Papuanatula tuber Lugo-Ortiz & McCafferty, 1999 , by original designation ( Lugo-Ortiz and McCafferty 1999)

Diagnosis.

Larval characters. The following combination of characters distinguishes Papuanatula from all other genera of Baetidae : antennal scapes basally narrow, distally broad; labrum much wider than long; labium with glossae much shorter than paraglossae; maxillary palp with two segments; both mandibles outside laterally with some long, robust, simple setae; outer side of each femur usually with single regular row of long, hair-like setae; femoral patch absent on all legs; patella-tibial suture usually present on all legs; tibia-tarsal condylus (originally located on outer side) turned to anterior side; anterior side of each tibia usually with regular row of setae similar to that on femur; anterior side of each tarsus usually with regular row of setae similar to femur and tibia; tarsus with conspicuous, long seta subdistally on inner margin; claw with single row of denticles and one or several posterior setae; hind protoptera absent or vestigial; tergalii present on abdominal segments II – VII; paraproct usually with prolongation on proximal margin; cerci usually longer than body length; paracercus strongly reduced or vestigial.

Redescription.

Larva. Head. Antenna. Scape basally narrow, distally broader. Labrum (Fig. 3 a, b ). Sub-rectangular, laterally convex to angulate, much wider than long. Distal margin with medial, shallow emargination. Ventrally with long, feathered setae on medial margin; several small, stout setae near anterolateral margin. Right mandible (Fig. 3 e ). Long, with incisor elongated (blade-like; usually worn toward the end of each instar); or shortened, incisor without elongation. Prostheca stick-like, distally denticulate; margin between prostheca and mola straight, usually with minute denticles; mola with setae on proximal corner. Left mandible (Fig. 3 f ). Long, with incisor elongated (blade-like; usually worn toward the end of each instar); or shortened, incisor without prolongation. Prostheca robust, distolaterally denticulate; margin between prostheca and mola straight, usually with minute denticles; mola with setae on proximal corner. Both mandibles with outer lateral margins almost straight or slightly convex, mediolaterally with some long, robust, simple setae near margin. Hypopharynx and superlinguae (Fig. 3 d ). Lingua at least slightly longer than superlinguae. Apex of lingua with well-developed, broad bunch of setae-like spines (exceptionally pair of bunches). Distolateral margin of superlinguae with medium, fine setae; lateral margins almost straight. Maxilla (Fig. 3 g ). Apically with three stout canines and three denti-setae; distal denti-seta tooth-like, slightly bent against canines; other denti-setae slender and pectinate; galea-lacinia usually with two stout, simple setae under canines; medially with one medium, feathered seta and 3–5 medium to long spine-like setae. Maxillary palp with two segments, apex with short point. Labium (Fig. 3 c ). Glossae basally broad, narrowing towards apex, shorter or much shorter than paraglossae; with several long setae at apex and usually one long seta near middle of ventral side. Apex of paraglossae with three rows of long, robust, distally pectinate setae; ventrally usually with one or several short, simple setae in distomedial area; dorsally with two or three long, spine-like setae near inner margin. Labial palp with three segments; segment II with distomedial protuberance hardly developed or absent, or with well-developed, distomedial protuberance; dorsally with row of several long, spine-like setae near outer, distolateral margin.

Thorax. Sterna (Figs 106 d , 108 a ). In some species, each thoracic sternum with pair of small protuberances: prothorax with pair of protuberances on lateral sides of prosternal sclerite; mesothorax and metathorax each with pair of such protuberances close to openings of sternal apodemes. Terga. Partly with conspicuous protuberances; surface usually with small, scattered scales, often with species-specific shape. Hind protoptera absent or vestigial. Legs (Figs 4 a – e , 108 b ). Long and slender, with long femur and tibia and relatively short tarsus. Femur. Outer side of each femur usually with single regular row of long, hair-like setae; inner margin with row of short, spine-like setae; femoral patch absent on all legs; apex on posterior side usually with row of short, fine setae. Tibia. Patella-tibial suture usually present on all legs (the only exception is P. (Papuanatula) normungulata sp. nov. from Sulawesi). Tibia-tarsal condylus (originally located on outer side) turned to anterior side. Anterior (originally outer-anterior) side of each tibia usually with regular row of setae similar to that on femur. Posterior surface usually with scattered, very short, stout setae. Tarsus. Anterior (originally outer) side of each tarsus usually with regular row of setae similar to femur. Claw. Slender, apically bent, pointed, with one row of denticles; usually one, sometimes several posterior setae.

Abdomen. Terga (Figs 8 a, b , 12 a , 13 a ). Partly with striking, species-specific protuberances; surface usually with small, scattered scales, often with species-specific shape. Posterior margins with denticles of different shape. Sterna. Posterior margins smooth, without denticles. Tergalii. Present on segments II – VII, in dorsolateral position. Margin smooth, sometimes with minute denticles; with short, simple setae. Paraproct (Figs 5 h , 12 e ). Median margin usually with minute denticles; posterior margin often with prolongation. Cercotractor usually with minute, marginal spines. Caudalii. Cerci usually longer than body length, swimming setae strongly diminished and reduced, or vestigial. Paracercus short or vestigial.

Description.

Male imago. Fore wings. With marginal double intercalary veins. Hind wings absent. Genitalia. Sterno-styliger muscle completely absent. Gonostyli segment II without significant widenings. Segment III (terminal) of gonostyli nearly as wide as segment II, length varying from slightly exceeding width to twice width.

Distribution.

Papua New Guinea, Indonesia: New Guinea, Sulawesi.

Figures

Figure 3. Papuanatula (Papuanatula) bessa, larva (from Waena): a, b labrum c labium d hypopharynx e, f left and right mandibles g maxilla.

Figure 4. Papuanatula (Papuanatula) bessa, larva (a – e from Wagau, Herzog Mts.): a foreleg b fore claw c hind tibia, inner margin d hind tibia, posterior surface e femur, posterior apex f, g tergalius IV (type locality) h paracercus (type locality) I cercus section (type locality). Scale bars: 50 µm (a); 10 µm (b – d, g, i); 20 µm (f, h).

Figure 5. Papuanatula (Papuanatula) bessa, larva, abdomen (from Waena): a tergum I b, c tergum II d apex of protuberance on tergum III e tergum IV f tergum V g tergum IX h paraprocts.

Figure 8. Papuanatula (Papuanatula) copis, larva, habitus: a dorsal view b lateral view c ventral view. Scale bars: 1 mm.

Figure 12. Papuanatula (Papuanatula) copis, larva: a metanotum and abdominal terga b abdominal terga c paracercus (type locality) d cercus (type locality) e paraproct (type locality) f cercotractor (type locality) g paraproct, distal margin (type locality). Scale bars: 100 µm (a); 10 µm (b, d – g); 20 µm (c).

Figure 13. Papuanatula (Papuanatula) copis, larva, SEM: a dorsal view b pronotum. Scale bars: 0.5 mm (a); 300 µm (b).

Figure 106. Papuanatula (Papuanatula) parvatubera sp. nov., larva: a hind leg b middle tarsus and claw (arrow: posterior seta) c male head, mature d prosternum e paracercus f cercus, dorsal view g cercus, lateral view. Scale bars: 50 µm (a); 10 µm (b, f, g); 100 µm (c); 20 µm (d, e).

Figure 108. Papuanatula (Papuanatula) parvatubera sp. nov., larva (SEM): a pro-, meso-, and metasternum (arrows: protuberances) b hind claw c abdominal terga III – V d abdominal terga VII – X e abdominal tergum IV f abdominal tergum VIII. Scale bars: 200 µm (a); 40 µm (b); 100 µm (c, d); 30 µm (e); 20 µm (f).