Labiobaetis hattam, 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 hattam sp. nov.

Type material.

Holotype. Indonesia • larva; Papua Barat, Fumato to Kebar, forest stream; 00°52'29"S, 132°46'06"E; 492 m; 06.xi.2013; leg. UNIPA team; BH030; on slide; GBIFCH00592775; MZB. Paratypes. Indonesia • 3 larvae; same data as holotype; 2 on slides; GenBank MW868311; GBIFCH00763707, GBIFCH00592704; 1 in alcohol; GBIFCH00515652; MZB, MZL.

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of one plus six long, simple setae (Fig. 8a); B) labial palp segment II with narrow, extended, distomedial protuberance, segment III slightly pentagonal (Fig. 8h); C) fore femur rather slender, length ca. 4 × maximum width, dorsal margin with 19-23 spine-like setae (Fig. 9a); D) hind protoptera absent; E) six pairs of gills (gill I absent), margin with short setae only; F) paraproct distally slightly expanded, with 38-48 stout, marginal spines (Fig. 9g); G) Scape apically with stout setae (Fig. 9h).

Description.

Larva (Figs 8, 9, 18a, b). Body length 7.0-7.6 mm. Cerci and paracercus broken. Antenna: approx. 3 × as long as head length.

Colouration (Fig. 18a, b). Head, thorax and abdomen dorsally dark brown, with pattern as in Fig. 18a; fore protoptera brown with bright stripes. Thorax ventrally ecru, abdomen ventrally brown, with pattern as in Fig. 18b. Legs light brown; femur with dorsomedial and apical brown spots; tibia medially and tarsus proximally brown. Caudalii brown.

Antenna (Fig. 9h) with scape and pedicel sub cylindrical, without distolateral process at scape. Scape apically with few stout setae.

Labrum (Fig. 8a). Sub-rectangular, length 0.8 × 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 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. 8b, 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 almost straight. Tuft of setae at apex of mola present.

Left mandible (Fig. 8d, 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 almost 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. 8f). Lingua approx. as long as superlingua. 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. 8g). 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 four or five long, simple setae. Maxillary palp ca. 1.1 × 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, apically constricted.

Labium (Fig. 8h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ten spine-like setae, increasing in length distally; apex with three long, robust, pectinate setae and one short, robust seta; outer margin with six or seven 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 and two or three short, simple setae in anteromedial area; dorsally with a row of six or seven long, spine-like setae near inner margin. Labial palp with segment I 0.9 × length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II with narrow, extended, distomedial protuberance; distomedial protuberance 0.6 × width of base of segment III; ventral surface with short, simple setae; dorsally with three or four spine-like setae near outer margin. Segment III slightly pentagonal; length 0.9 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 9i) absent.

Foreleg (Fig. 9a-d). Ratio of foreleg segments 1.3:1.0:0.6:0.2. Femur. Length ca. 4 × maximum width. Dorsal margin with a row of 19-23 curved, spine-like, apically rounded setae; length of setae 0.1 × 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; femoral patch present. On posterior side apically with stout setae. Tibia. Dorsal margin with a row of short, spine-like setae and fine, simple 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 10-12 denticles; distally pointed; with ca. six stripes; subapical setae absent.

Middle and hind legs (Fig. 9d). As foreleg, also with femoral patch. Stout setae on apex of posterior side present on middle leg and absent on hind leg.

Terga (Fig. 9e). Surface with irregular rows of U-shaped scale bases and scattered micropores. Posterior margin of tergum IV with triangular spines, longer than wide.

Gills (Fig. 9f). 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 VI combined. Gill VII as long as length of segments VIII and 2/3 IX combined.

Paraproct (Fig. 9g). Distally slightly expanded, with 38-48 stout, marginal spines. Surface scattered with U-shaped scale bases and micropores. Cercotractor with numerous small, marginal spines.

Etymology.

Dedicated to the indigenous Hattam people from West Papua.

Distribution.

Indonesia: Papua Barat (Fig. 21c).

Biological aspects.

The specimens were collected in a forest stream at an altitude of 500 m.