Labiobaetis toraja, 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 toraja sp. nov.

Type material.

Holotype. Indonesia • larva; Sulawesi; Tengah, Lake Lore; 01°19'35"S, 120°18'40"E; 1600 m; 01.ix.2011; leg. Sumoked (SUL013); on slide; GBIFCH00592443; MZB. Paratypes. Indonesia • 9 larvae; same data as holotype; 2 on slides; GBIFCH00592444, GBIFCH00592446; 7 in alcohol; GenBank MW868315, MW868316; GBIFCH00674627, GBIFCH00674628, GBIFCH00515619, GBIFCH00515620, GBIFCH00515596; MZB, MZL.

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of one plus 18-21 long, feathered setae (Figs 6a, 4b); B) labial palp segment II with hook-like distomedial protuberance, segment III oblong; glossae much shorter than paraglossae (Fig. 6h); C) left mandible with setae at apex of mola; D) fore femur length ca. 3 × maximum width, dorsal margin with 18-25 curved, spine-like setae (Fig. 7a); E) claw with long subapical seta on posterior side and reduced subapical seta on anterior side (Figs 4b, 7d); F) hind protoptera absent; G) six pairs of gills (gill I absent); H) paraproct distally slightly expanded, with more than 40 stout, marginal spines.

Description.

Larva (Figs 4b, 6, 7, 17b, c). Body length 5.5-6.5 mm. Cerci broken. Paracercus: ca. 0.4 × body length. Antenna: approx. twice as long as head length.

Colouration (Fig. 17b, c). Head, thorax and abdomen dorsally brown, with pattern as in Fig. 17b. Head, thorax and abdomen ventrally light brown, abdominal segments VII-IX laterally darker (Fig. 17c). Legs light brown; femur with dorsomedial brown streak and brown sections apically and distoventrally; tibia basally and tarsus distally darker (Fig. 17c). Caudalii ecru.

Antenna (Fig. 7h) with scape and pedicel sub cylindrical, without distolateral process at scape. Scape and pedicel with few stout setae.

Labrum (Fig. 6a). 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 18-21 long, feathered setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid setae; ventral surface with ca. seven short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 6b, c). Incisor and kinetodontium fused. Incisor with five 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 straight. Tuft of setae at apex of mola present.

Left mandible (Fig. 6d, e). Incisor and kinetodontium fused. Incisor with five denticles; kinetodontium with three denticles. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola straight, with few minute denticles. 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 slightly convex. Basal half with fine, simple setae scattered over dorsal surface.

Hypopharynx and superlinguae (Fig. 6f). Lingua shorter than superlingua. Lingua approx. as long as broad; distal half laterally not expanded; medial tuft of stout setae well developed and long. Superlinguae distally rounded; lateral margins rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 6g). Galea-lacinia ventrally with five 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 6-8 long, simple setae. Maxillary palp ca. 1.3 × length of galea-lacinia; 2-segmented; palp segment II 1.2 × 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.

Labium (Fig. 6h, i). Glossa basally broad, narrowing toward apex; much shorter than paraglossa; inner margin with two spine-like setae; apex with two long and one medium, robust setae; outer margin with three spine-like setae; ventral surface with fine, simple, scattered setae. Paraglossa broad, slightly curved inward; outer margin convex; apex rounded; with three long rows of long, robust, distally pectinate setae in apical area, five or six short, simple setae in anteromedial area and one short, simple seta in posteromedial area; dorsally with a row of four long, spine-like setae near inner margin. Labial palp with segment I 0.8 × length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II with hook-like, distomedial protuberance; distomedial protuberance 0.9 × width of base of segment III; ventral surface with short, simple setae; dorsally with one or two spine-like setae near outer margin. Segment III oblong; length 1.7 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 7i) absent.

Foreleg (Fig. 7a-d). Ratio of foreleg segments 1.2:1.0:0.6:0.2. Femur. Length ca. 3 × maximum width. Dorsal margin with a row of 18-25 curved, spine-like setae and a row of long, fine, simple setae; length of setae 0.21 × maximum width of femur. Apex rounded, with a pair of spine-like setae and some short, stout setae. Stout, apically rounded setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin with a row of short, 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 2/3 area. Tarsus. Dorsal margin with a row of short, spine-like setae. Ventral margin with a row of curved, spine-like setae and a row of short, stout setae near margin. Claw with one row of nine or ten denticles; distally pointed; with ca. four stripes; with long, subapical seta on posterior side and reduced, subapical seta on anterior side.

Middle and hind legs. As foreleg, but middle leg with a reduced femoral patch and hind leg with a rather well developed femoral patch.

Terga (Fig. 7e). Surface with irregular rows of U-shaped scale bases. Posterior margin of tergum IV with triangular, apically rounded spines, slightly longer than wide, and fine simple setae.

Gills (Fig. 7f). Present on segments II-VII. Margin with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Gill IV as long as length of segments V and 1/2 VI combined. Gill VII as long as length of segment VIII.

Paraproct (Fig. 7g). Distally slightly expanded, with more than 40 stout, marginal spines. Surface scattered with U-shaped scale bases, fine, simple setae and micropores. Cercotractor with numerous small, marginal spines.

Etymology.

Dedicated to the indigenous Toraja people of Sulawesi, where the type locality is located.

Distribution.

Indonesia: Sulawesi (Fig. 21b).

Biological aspects.

The specimens were collected at an altitude of 1600 m in a tributary to Lake Lore.