Labiobaetis amber, 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/289249EE-9562-44D6-A5F5-A602900CB96A
taxon LSID	lsid:zoobank.org:act:289249EE-9562-44D6-A5F5-A602900CB96A
treatment provided by	Alpine Entomology by Pensoft
scientific name	Labiobaetis amber
status	sp. nov.

Treatment

5. Labiobaetis amber sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 38 View Figure 38

Diagnosis.

Larva. Following combination of characters differentiates L. amber sp. nov. from other species of the group Labiobaetis petersorum : A) labrum length 0.6 × maximal width (Fig. 2a View Figure 2 ); B) both mandibles without denticles between prostheca and mola (Fig. 2d, f View Figure 2 ); C) labial palp segment II with broadly rounded, thumb-like, distomedial protuberance; segment III nearly oblong (Fig. 4d View Figure 4 ); D) paraglossa dorsally with row of four long, spine-like setae near inner, distal margin (Fig. 4c View Figure 4 ); E) tibia with row of medium, stout, apically rounded setae on dorsal margin (Fig. 5f View Figure 5 ); posterior surface scattered with short, lanceolate setae (Fig. 5h View Figure 5 ); F) claw with ca. ten denticles (Fig. 5k View Figure 5 ); G) posterior margin of abdominal tergum IV with triangular, pointed spines, mostly slightly wider than long (Fig. 6c View Figure 6 ).

Description.

Larva (Figs 1 View Figure 1 - 7 View Figure 7 ). Body length 6.2-8.2 mm. Cerci: ca. 3/4 of body length. Paracercus: ca. 1/2 of cerci length. Antenna: approx. twice as long as head length.

Cuticular colouration (Fig. 1a, b View Figure 1 ). Head, thorax and abdomen dorsally mainly brown, with pattern as in Fig. 1a View Figure 1 . Forewing pads light brown with dark brown and grey stripes; abdominal tergum I grey with brown streak along distal margin; terga II-IV grey-brown, laterally brighter, with distolateral brown spots; terga V-VI off-white, laterally with darker areas; terga VII-VIII dark brown, laterally with whitish streak, medially with light brown line; tergum IX grey-brown with bright area medially; tergum X off-white. Thorax and abdomen ventrally grey-white, sterna VII-VIII darker. Legs off-white, femur medially with large grey area, with large blanks in distal and proximal area; tarsus distally grey-brown. Caudalii grey.

Hypodermal colouration (Fig. 6b View Figure 6 ). Antenna with dark brown dots in middle part of flagellum.

Antenna (Fig. 6a, b View Figure 6 ) with scape and pedicel sub-cylindrical, without distolateral process at scape.

Labrum (Fig. 2a, b View Figure 2 ). Sub-rectangular, length 0.6 × 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 lateral and anterolateral long, feathered setae and medial long, bifid setae.

Right mandible (Fig. 2c, d View Figure 2 ). Incisor and kinetodontium fused. Incisor with three denticles, outer denticle blade-like enlarged; kinetodontium with four denticles, inner margin of innermost denticle with row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola straight, smooth. Tuft of setae at apex of mola present.

Left mandible (Fig. 2e, f View Figure 2 ). Incisor and kinetodontium fused. Incisor with four 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, smooth. Subtriangular process rather short, basally broad, 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. 3a View Figure 3 ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, distolaterally with two additional tufts of setae; distal half laterally not expanded. Superlinguae distolaterally protruding; lateral margins angulate; fine, long, simple setae along distal margin.

Maxilla (Fig. 3b, d View Figure 3 ). 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. six long, simple setae. Maxillary palp slightly longer than length of galea-lacinia; 2-segmented; palp segment II slightly longer and narrower than segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment without distolateral excavation, apically pointed, constricted.

Labium (Fig. 4a-e View Figure 4 ). Glossa basally broad, narrowing toward apex; much shorter than paraglossa; inner margin with ca. nine spine-like seta; apex with three long, robust, apically pectinate setae; outer margin with ca. five 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 ca. two short, simple setae in anteromedial area; dorsally with four long, spine-like setae near inner margin. Labial palp with segment I slightly shorter than length of segments II and III combined. Segment II with broadly rounded, thumb-like, distomedial protuberance; distomedial protuberance 0.5 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with row of ca. six spine-like setae near outer margin. Segment III nearly oblong; length 1.1 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera absent.

Legs (Figs 5a-k View Figure 5 , 7 View Figure 7 ). Ratio of foreleg segments 1.4:1.0:0.6:0.2. Femur. Fore femur length ca. 2.7 × maximum width, middle and hind femur less wide. Dorsal margin with a row of ca. 50 curved, spine-like setae; length of setae 0.16 × maximum width of femur. Apex rounded, with many short, stout, lanceolate setae. Apex on posterior side with short, stout, apically truncate 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 medium, stout, apically rounded 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 setae along patellatibial suture. Posterior surface with short, stout, apically rounded, scattered setae. Patellatibial suture present on basal half. Tarsus. Dorsal margin with row of short, spine-like setae. Ventral margin with row of curved, spine-like setae increasing in length distally. Claw with one row of ca. ten denticles; distally pointed; with long, fine, transparent subapical seta on posterior side and short subapical seta on anterior side.

Abdominal terga (Fig. 6c View Figure 6 ). Surface with irregular rows of U-shaped scale bases. Posterior margin of terga: I smooth, without spines; II-VII with triangular spines, mostly slightly wider than long; VIII-IX with spines becoming slenderer and longer.

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

Tergalii (Fig. 6d, e View Figure 6 ). 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 ½ VI combined. Tergalius VII as long as length of segment VIII and ½ IX combined.

Paraproct (Fig. 6f View Figure 6 ). Distally not expanded, with ca. 33 stout, marginal spines. Surface scattered with U-shaped scale bases. Cercotractor with numerous small, marginal spines.

Etymology.

With reference to Amber village, the type locality of the species.

Distribution.

Indonesia, Papua Prov. (Fig. 38a View Figure 38 ).

Biological aspects.

The specimens were collected at an altitude of 1200 m.

Type material.

Holotype. INDONESIA • larva; Papua Prov., River Je, Loc. Arfak, East of Amber village; 01°10'59"S, 133°54'44"E; 1200 m; 16.vi.2016, leg. Sumoked and M. Balke; (BH 68); on slide; GBIFCH00763716; MZB. Paratypes. INDONESIA • 28 larvae; same data as holotype; 2 on slides; GBIFCH00763717, GBIFCH00592774; MZL; 23 in alcohol; GBIFCH00515646, GBIFCH00515647, GBIFCH00975600, GBIFCH00975607, GBIFCH00975712; MZL.