Labiobaetis bilibil, Kaltenbach & Vuataz & Gattolliat, 2023

Kaltenbach, Thomas, Vuataz, Laurent & Gattolliat, Jean-Luc, 2023, New species of Labiobaetis Novikova & Kluge from New Guinea (Ephemeroptera, Baetidae): a never-ending story of diversity, Alpine Entomology 7, pp. 83-134 : 83

publication ID	https://dx.doi.org/10.3897/alpento.7.106089
publication LSID	lsid:zoobank.org:pub:EC4C4A0E-A1F0-4555-B5D4-A4F18AFED1AD
persistent identifier	https://treatment.plazi.org/id/0AC9992D-3D71-47B1-824D-81526F0B9C5D
taxon LSID	lsid:zoobank.org:act:0AC9992D-3D71-47B1-824D-81526F0B9C5D
treatment provided by	Alpine Entomology by Pensoft
scientific name	Labiobaetis bilibil
status	sp. nov.

Treatment

6. Labiobaetis bilibil sp. nov.

Figs 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10 , 11 View Figure 11 , 12 View Figure 12 , 13 View Figure 13 , 38 View Figure 38

Diagnosis.

Larva. Following combination of characters differentiates L. bilibil sp. nov. from other species of the group Labiobaetis petersorum : A) labrum length 0.5 × maximal width (Fig. 9a View Figure 9 ); B) both mandibles with row of minute denticles between prostheca and mola (Fig. 9e, h View Figure 9 ); C) labial palp segment II with extended, slightly hooked, distomedial protuberance; segment III conical (Fig. 10c View Figure 10 ); D) paraglossa dorsally with row of 2-4 long, spine-like setae near inner, distal margin (Fig. 10b View Figure 10 ); E) tibia with row of short and medium, stout, lanceolate, pointed setae on dorsal margin (Fig. 12a, e View Figure 12 ); posterior surface scattered with short, lanceolate setae (Fig. 12g View Figure 12 ); F) claw with ca. eight denticles (Fig. 12k View Figure 12 ); G) posterior margin of abdominal tergum IV with triangular, pointed spines, longer than wide (Fig. 13c View Figure 13 ).

Description.

Larva (Figs 8 View Figure 8 - 13 View Figure 13 ). Body length 8.8-9.5 mm. Cerci: broken. Paracercus: ca. 0.4 × body length. Antenna: approx. 2.5 × as long as head length.

Cuticular colouration (Fig. 8a, b View Figure 8 ). Head, thorax and abdomen dorsally brown, with pattern as in Fig. 8a View Figure 8 . Forewing pads light brown with dark brown and grey stripes; abdominal terga II-IV and VII-VIII darker. Thorax ventrally grey; abdominal sternum I grey, II-V beige and VI-X light brown to brown. Legs brown with brighter areas, femur with elongate proxomedial and distodorsal blanks. Caudalii light brown.

Hypodermal colouration (Fig. 13b View Figure 13 ). Antenna with dark brown dots in middle part of flagellum.

Antenna (Fig. 13a, b View Figure 13 ) with scape and pedicel sub-cylindrical, without distolateral process at scape.

Labrum (Fig. 9a, b View Figure 9 ). Sub-rectangular, length 0.5 × maximum width. Distal margin with medial emargination and small process. Dorsally with medium, fine, simple setae scattered over surface; submarginal arc of setae composed of ca. ten long, simple setae. Ventrally with marginal row of setae composed of anterolateral long, feathered setae and medial long, bifid setae.

Right mandible (Fig. 9c-e View Figure 9 ). Incisor and kinetodontium fused. Incisor with three denticles, outer denticle blade-like enlarged; kinetodontium with three denticles, inner margin of innermost denticle with row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola straight, with row of minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 9f-h View Figure 9 ). Incisor and kinetodontium fused. Incisor with three denticles, outer denticle blade-like enlarged; kinetodontium with three denticles. Prostheca robust, apicolaterally with small denticles and comb-shaped structure. Margin between prostheca and mola straight, with row of minute denticles. Subtriangular process above level of area between prostheca and mola. Tuft of setae at apex of mola present.

Both mandibles with lateral margins almost straight.

Hypopharynx and superlinguae (Fig. 10a View Figure 10 ). Lingua longer as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, distolaterally with two additional tufts of setae; distal half laterally slightly expanded. Superlinguae distolaterally protruding; lateral margins angulate; fine, long, simple setae along distal margin.

Maxilla (Fig. 10b-d View Figure 10 ). Galea-lacinia ventrally with two simple, apical setae below canines. Inner dorsal row of setae with three denti-setae, distal denti-seta tooth-like, middle and proximal denti-setae slender, bifid and pectinate. Medially with one feathered spine-like seta and ca. eight long, simple setae. Maxillary palp approx. as long as length of galea-lacinia; 2-segmented; palp segment II approx. as long and much narrower as segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment without distolateral excavation, apically slightly pointed, constricted.

Labium (Fig. 11a-d View Figure 11 ). Glossa basally broad, narrowing toward apex; much shorter than paraglossa; inner margin with ca. seven spine-like seta; apex with three long, robust, apically pectinate setae; outer margin with ca. six spine-like setae; ventral surface with fine, simple, scattered setae. Paraglossa sub-rectangular, slightly curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and one short, simple seta in anteromedial area; dorsally with 2-4 long, spine-like setae near inner margin. Labial palp with segment I approx. as long as length of segments II and III combined. Segment II with elongate, slightly hooked distomedial protuberance; distomedial protuberance 0.6 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with row of ca. five spine-like setae near outer margin. Segment III conical; length approx. width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera absent.

Legs (Fig. 12a-k View Figure 12 ). Ratio of foreleg segments 1.6:1.0:0.7:0.2. Femur. Fore femur length ca. 2.3 × maximum width, middle and hind femur less wide. Dorsal margin with a row of ca. 55 curved, spine-like setae, in proximal part a partial 2nd row; length of setae 0.13 × maximum width of femur. Apex rounded, with many short, stout, spine-like, pointed setae. Apex on posterior side with short, stout, apically pointed setae on fore and middle leg, absent on hind leg. Stout, lanceolate, pointed setae scattered along ventral margin, few such setae on surface of distomedial half; femoral patch reduced on fore and middle leg, well developed on hind leg. Tibia. Dorsal margin with row of short and medium, stout, lanceolate, pointed setae. Ventral margin with row of short, curved, spine-like setae, on apex a tuft of fine, simple setae. Anterior surface with short, stout, lanceolate, pointed setae mostly along patellatibial suture. Posterior surface with short, stout, apically rounded, scattered setae. Patellatibial suture present on basal 4/5 area. Tarsus. Dorsal margin with row of short, spine-like setae. Ventral margin with row of curved, spine-like setae increasing in length distally, and row of short, spine-like setae near ventral margin. Claw with one row of ca. eight denticles; distally pointed; with long, fine, transparent subapical seta on posterior side.

Abdominal terga (Fig. 13c View Figure 13 ). Surface with irregular rows of U-shaped scale bases. Posterior margin of terga: I smooth, without spines; II-IX with triangular, sharply pointed spines, longer than wide.

Abdominal sterna. Posterior margin of sterna: I-V smooth, without spines; VI-IX with small, triangular spines.

Tergalii (Fig. 13d, e View Figure 13 ). Present on segments II-VII. Margin with small denticles intercalating fine, simple setae. Anal margin with both short and long, fine setae. Tracheae extending from main trunk to inner and outer margins. Tergalius IV as long as length of segments V and VI combined. Tergalius VII as long as length of segments VIII and ½ IX combined.

Paraproct (Fig. 6f View Figure 6 ). Distally not expanded, with ca. 21 stout, marginal spines. Surface scattered with U-shaped scale bases. Cercotractor with numerous small, marginal spines.

Etymology.

Dedicated to the indigenous Bilibil people of the Madang region, where the type locality is.

Distribution.

Papua New Guinea (Fig. 38a View Figure 38 ).

Biological aspects.

The specimens were collected at an altitude of 350 m.

Type material.

Holotype. PAPUA NEW GUINEA • larva; Madang Prov., Adalbert Mts., Sewan; 04°41'01"S, 145°26'55"E, 350 m; 03.v.2006; leg. M. Balke and Manaono; (PNG 50); on slide; GBIFCH00592772; ZSM. Paratypes. PAPUA NEW GUINEA • 19 larvae; same data as holotype; 4 on slides; GBIFCH00592571, GBIFCH00592572, GBIFCH00592573, GBIFCH00763602; MZL; 15 in alcohol; GBIFCH00515641, GBIFCH00515642, GBIFCH00975601, GBIFCH00975616, GBIFCH00975711; MZL.