Labiobaetis claudiae, Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2018

Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2018, The incredible diversity of Labiobaetis Novikova & Kluge in New Guinea revealed by integrative taxonomy (Ephemeroptera, Baetidae), ZooKeys 804, pp. 1-136 : 13-18

4. Labiobaetis claudiae sp. n. Figures 8, 9, 58d, 64a

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal submarginal arc of setae composed of one plus five long, simple setae; B) labial palp segment II with an elongated thumb-like distomedial protuberance, segment III subrectangular; C) fore femur rather broad, length ca. 3 × width, dorsal margin with a row of ca. 27 curved, spine-like setae; D) gills with small denticles and both medium and long, fine simple setae on margin; E) paraproct distally not expanded, with ca. 18 marginal, stout spines.

Description.

Larva (Figs 8, 9, 58d). Body length 5.3 mm; antenna: approximately twice as long as head length.

Colouration. Head, thorax and abdomen dorsally brown, head and thorax with bright median, dorsal suture, thorax with bright pattern as in Fig. 58d, abdominal segments I, V, VI, IX and X light brown, other segments dark brown. Head, thorax and abdomen ventrally light brown, legs transparent with brown spots distomedially on femur and proximally on tibia and tarsus, caudal filaments brown.

Antenna with scape and pedicel sub-cylindrical, without distolateral process at scape; flagellum with broad, lanceolate spines and fine, simple setae on apex of each segment.

Labrum (Fig. 8a). Rectangular, length 0.6 × 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 five long, simple setae. Ventrally with marginal row of setae composed of anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with seven short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 8b, c). Incisors fused. Outer and inner sets of denticles with 4 + 4 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. 8d, e). Incisors fused. Outer and inner sets of denticles with 3 + 3 denticles and one minute intermediate denticle. Prostheca robust, apically with small denticles and comb-shape 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 (Fig. 8f). Lingua shorter than superlingua. Lingua longer than broad; medial tuft of stout setae present; distal half laterally expanded. Superlingua straight; lateral margin straight; fine, long, simple setae along distal margin.

Maxilla (Fig. 8g). Galea-lacinia with one simple, robust apical seta under crown. 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 bipectinate, spine-like seta and 5-6 long, simple setae. Maxillary palp slightly longer than length of galea-lacinia; two segmented. Palp segment II 1.3 × length of segment I. Setae on maxillary palp fine and simple, scattered over surface of segments I and II. Apex of last segment constricted, without excavation at inner distolateral margin.

Labium (Fig. 8h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with six spine-like setae increasing in length distally; apex with three long, robust setae; outer margin with 4-5 long, spine-like setae increasing in length distally; ventral surface with fine, simple, scattered setae. Paraglossa sub-rectangular, curved inward, apex rounded; ventrally with three rows of long, robust, distally pectinate setae in apical area and a row of 3-4 medium, simple setae in anteromedial area; dorsally with a row of 3-4 long, spine-like setae near inner margin. Labial palp with segment I 0.8 × length of segments II and III combined. Segment I covered with short, fine, simple setae ventrally and micropores dorsally. Segment II with an elongated, thumb-like distomedial protuberance; distomedial protuberance 0.4 × width of base of segment III; inner and outer margin both with short, fine, simple setae; dorsally with row of three long, spine-like setae in anteromedial area. Segment III subrectangular; apex truncate; length 0.9 × width; ventrally covered with medium spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg (Fig. 9a, b). Ratio of foreleg segments 1.3:1.0:0.6:0.2. Femur. Length ca. 3 × maximum width. Dorsal margin with a row of ca. 27 curved, spine-like setae; length of setae 0.16 × maximum width of femur. Apex rounded; with two pairs of curved, spine-like setae and some short, stout setae. Many stout, lanceolate setae scattered along the ventral margin; femoral patch well developed. Tibia. Dorsal margin with a row of stout, lanceolate setae and very fine, simple setae. Ventral margin with a row of curved, spine-like setae, on apex one stout, spine-like seta and a tuft of long, fine, simple setae. Anterior surface scattered with stout, lanceolate setae. Tibio-patellar suture present on basal 2/3 area. Tarsus. Dorsal margin with a row of short, curved, spine-like setae. Ven tral margin with a row of curved, spine-like setae. Tarsal claw with one row of 12-13 denticles; distally pointed; with eight stripes; subapical setae absent.

Tergum (Fig. 9c). 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. 9d). Present on segments II–VII. Margin with small denticles intercalating both medium 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 IX combined.

Paraproct (Fig. 9e). Distally not expanded, with ca. 18 marginal, stout spines. Surface scattered with U-shaped scale bases and fine, simple setae and micropores. Postero-lateral extension (cercotractor) with small marginal spines.

Etymology.

Dedicated to Claudia Kaltenbach, the wife of one of the authors (TK) for her constant support during the study.

Distribution.

New Guinea.

Biological aspects.

The specimens were collected in a ford at an altitude of 80 m a.s.l.

Type-material.

Holotype. Nymph (on slide, GBIFCH 00508144), Papua New Guinea, Madang, highway nr Madang, ford, 80 m, 26 Nov and 2-3 Dec 2006, 05°24.41'S, 145°38.21'E, Binatang Boys (PNG 117). Deposited in ZSM. Paratypes. 4 nymphs (2 on slide, GBIFCH 00508145, GBIFCH 00465165, 2 in alcohol, GBIFCH 00515229, deposited in MZL), same data as holotype.