Labiobaetis werneri, Kaltenbach & Gattolliat, 2021

Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2021, New species of Labiobaetis Novikova & Kluge from Southeast Asia and New Guinea (Ephemeroptera, Baetidae), ZooKeys 1067, pp. 159-208 : 159

Labiobaetis werneri sp. nov.

Type material.

Holotype. Papua New Guinea • larva; Gulf, Marawaka, Mala; 07°05'40"S, 145°44'28"E; 1400 m; 11.xi.2006; leg. Balke and Kinibel; (PNG 90); on slide; GenBank MW868307; GBIFCH00763699; ZSM. Paratypes. Papua New Guinea • 1 larva; same data as holotype; in alcohol; GBIFCH00515645; MZL • 1 larva; Eastern Highlands, Marawaka, Ande; 07°01'42"S, 145°49'48"E; 1700-1800 m; 09.xi.2006; leg. Balke and Kinibel; (PNG 87); on slide; GenBank MW868309; GBIFCH00763603; MZL • 10 larvae; Morobe, Wagau, Herzog Mts; 06°51'04"S, 146°48'04"E; 1150 m; 19.xi.2006; leg. Balke and Kinibel; (PNG 102); 1 on slide; GBIFCH00592773; MZL; 9 in alcohol; GenBank MW868308; GBIFCH00763700, GBIFCH00515644, GBIFCH00515651; MZL • 1 larva; Morobe, Garaina; 07°51'02"S, 147°07'00"E; 720 m; vi.2008; leg. Ibalim and Sosanika; (PNG216); in alcohol; GBIFCH00829895; MZL.

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of one plus six or seven long, simple setae (Fig. 10a); B) labial palp segment II with rather narrow thumb-like, distomedial protuberance, segment III sub-rectangular (Fig. 10h); C) fore femur rather broad, length 2.7 × maximum width, dorsal margin with 25-33 spine-like setae plus additional setae near margin (Fig. 11a); D) hind protoptera absent; E) six pairs of gills (gill I absent), anal margin with both short and long setae (Fig. 11e); F) paraproct distally not expanded, with 18-28 stout, marginal spines (Fig. 11f).

Description.

Larva (Figs 10, 11, 19a, b). Body length 5.7-6.2 mm. Cerci broken, paracercus ca. 0.4 × body length. Antenna: approx. 2.5 × as long as head length.

Colouration (Fig. 19a, b). Head, thorax and abdomen dorsally brown, with pattern as in Fig. 19a. Head, thorax and abdomen ventrally light brown, abdominal sternites VI-IX darker, as in Fig. 19b. Legs light brown; femur with dorsomedial and apical brown spots; tarsus distally brown. Caudalii light brown.

Antenna (Fig. 11g) with scape and pedicel sub cylindrical, without distolateral process at scape.

Labrum (Fig. 10a). Sub-rectangular, length 0.7 × maximum width. Distal margin with medial emargination and a small process. Dorsally with medium, fine, simple setae scattered over surface; submarginal arc of setae composed of one plus six or seven long, simple setae. Ventrally with marginal row of setae composed of anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with ca. seven short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 10b, c). Incisor and kinetodontium fused. Incisor with four denticles; kinetodontium with three denticles, inner margin of innermost denticle with a row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola almost straight. Tuft of setae at apex of mola present.

Left mandible (Fig. 10d, e). Incisor and kinetodontium fused. Incisor with four denticles; kinetodontium with three denticles. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola straight. Subtriangular process long and slender, above level of area between prostheca and mola. Denticles of mola apically constricted. Tuft of setae at apex of mola present.

Both mandibles with lateral margins almost straight. Basal half with fine, simple setae scattered over dorsal surface.

Hypopharynx and superlinguae (Fig. 10f). Lingua approx. as long as superlinguae. Lingua longer than broad; distal half laterally slightly expanded; medial tuft of stout setae well developed and short. Superlinguae distally rounded; lateral margins rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 10g). Galea-lacinia ventrally with two simple, apical setae under 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 pectinate, spine-like seta and 7-9 long, simple setae. Maxillary palp ca. 1.3 × length of galea-lacinia; 2-segmented; palp segment II 1.5 × length of segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment without excavation at inner distolateral margin, apically constricted.

Labium (Fig. 10h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with nine spine-like setae, increasing in length distally; apex with three long, robust, pectinate setae and one short, robust seta; outer margin with seven or eight spine-like setae; ventral surface with fine, simple, scattered setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area, three or four short, simple setae in anteromedial area and one short, simple seta in posterolateral area; dorsally with a row of five long, spine-like setae near inner margin. Labial palp with segment I 1.1 × length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II with narrow thumb-like, distomedial protuberance; distomedial protuberance 0.5 × width of base of segment III; ventral surface with short, simple setae; dorsally with 3-5 spine-like setae near outer margin. Segment III sub-rectangular; length 1.1 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 11h) absent.

Foreleg (Fig. 11a-c). Ratio of foreleg segments 1.6:1.0:0.9:0.3. Femur. Length 2.7 × maximum width. Dorsal margin with a row of 25-33 curved, spine-like setae and additional setae near margin; length of setae 0.16 × maximum width of femur. Apex rounded, with a pair of spine-like setae and some short, stout setae. Many stout, lanceolate setae scattered along ventral margin and some scattered on surface; femoral patch present. On posterior side apically with stout setae. Tibia. Dorsal margin with a row of short to medium, spine-like setae. Ventral margin with a row of short, curved, spine-like setae, on apex some longer setae and a tuft of fine, simple setae. Anterior surface scattered with stout, lanceolate setae. Patellotibial suture present on basal 1/2. Tarsus. Dorsal margin with a row of short, spine-like setae and fine, simple setae. Ventral margin with a row of curved, spine-like setae. Claw with one row of 9-12 denticles; distally pointed; with ca. five stripes; subapical setae absent.

Middle and hind legs (Fig. 11c). As foreleg, also with femoral patch. Stout setae on apex of posterior side present on middle leg and absent on hind leg.

Terga (Fig. 11d). Surface with irregular rows of U-shaped scale bases and scattered micropores. Posterior margin of tergum IV with triangular spines, wider than long.

Gills (Fig. 11e). Present on segments II-VII. Costal margin with small denticles intercalating short, fine simple setae; anal margin with small denticles, intercalating both short and long, fine, simple setae. Tracheae extending from main trunk to inner and outer margins. Gill IV as long as length of segments V and 2/3 VI combined. Gill VII as long as length of segments VIII and 1/2 IX combined.

Paraproct (Fig. 11f). Distally not expanded, with 18-28 stout, marginal spines. Surface scattered with U-shaped scale bases and fine, simple setae. Cercotractor with numerous small, marginal spines.

Etymology.

Dedicated to Werner Horzel, the late stepfather of the first author.

Distribution.

Papua New Guinea (Fig. 21c).

Biological aspects.

The specimens were collected at altitudes from 1150 m to 1800 m.