Labiobaetis podolakae, 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 : 51-56

15. Labiobaetis podolakae sp. n. Figures 28, 29, 60d, 65a

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal submarginal arc of setae composed of one plus six long, simple setae; B) maxillary palp 1.2 × length of galea-lacinia; C) labial palp segment II with a compact, rounded distomedial protuberance; D) fore femur rather broad, length ca. 3 × maximum width, dorsal margin with a row of ca. 16 curved, spine-like setae and a row of spine-like setae near margin; E) paraproct with three robust, lanceolate setae near distolateral margin.

Description.

Larva (Figs 28, 29, 60d). Body length 4.7 mm.

Colouration. Head, thorax and abdomen dorsally brown, head and thorax with bright median, dorsal suture, forewing pads with bright striation. Head, thorax and abdomen ventrally light brown, femur dorsal margin brown, legs otherwise colourless, caudal filaments light brown.

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

Labrum (Fig. 28a). Rectangular, length 0.7 × maximum width. Distal margin with medial emargination and a small process. Dorsally with many medium to long, fine, simple setae; submarginal arc of setae composed of one plus six long, simple setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with six short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 28b, c). Incisors fused. Outer and inner sets of denticles with 4 + 3 denticles plus one small intermediate denticle. Inner margin of innermost denticle with a row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola slightly convex, with minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 28d, e). Incisors fused. Outer and inner sets of denticles with 3 + 4 denticles. Prostheca robust, apically with small denticles and comb-shape struc ture. Margin between prostheca and mola straight, with minute denticles towards subtriangular process. 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. 28f). Lingua longer than superlingua. Lingua longer than broad; medial tuft of stout setae present; distal half laterally expanded. Superlingua rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 28g). Galea-lacinia with two simple, robust apical setae 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 five long, simple setae. Maxillary palp 1.2 × as long as length of galea-lacinia; two segmented. Palp segment II 1.4 × length of segment I. Setae on maxillary palp fine and simple, scattered over surface of segments I and II. Apex of last segment rounded, with slight excavation at inner distolateral margin.

Labium (Fig. 28h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with six spine-like setae increasing in length distally; apex with two long and one short, robust, pectinate setae; outer margin with five long, spine-like setae increasing in length distally; ventral surface with few short, fine, simple setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, apically pectinate setae; dorsally with 2-3 medium, simple setae; ventrally with three long, spine-like setae near inner margin. Labial palp with segment I 0.6 × length of segments II and III combined. Segment I covered with micropores dorsally and ventrally with fine, simple setae along margins. Segment II with a compact, rounded distomedial protuberance; distomedial protuberance 0.3 × width of base of segment III; inner and outer margin both with short, fine, simple setae; dorsally with a row of four long, spine-like, simple setae. Segment III conical; apex rounded; length 1.1 × width; ventrally covered with medium spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg (Fig. 29a, b). Ratio of foreleg segments 1.2:1.0:0.5:0.2. Femur. Length ca. 3 × maximum width. Dorsal margin with row of ca. 16 curved, spine-like setae and a row of stout, pointed setae near margin; length of setae 0.2 × maximum width of femur. Apex rounded; with one curved, spine-like seta and many short, stout, pointed setae. Many stout, lanceolate setae and a few fine, simple setae along ventral margin; femoral patch poorly developed. Tibia. Dorsal margin with a row of short, curved, spine-like setae and a row of long, fine, simple setae, and a row of stout, lanceolate setae near margin. Ventral margin with a row of short, spine-like setae, on apex one stout, spine-like seta and a tuft of long, fine, simple setae. Anterior surface scattered with many stout, lanceolate setae. Tibio-patellar suture present on basal 1/2. Tarsus. Dorsal margin with a row of short, spine-like setae and long, simple setae. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of nine denticles; distally pointed; with three stripes; subapical setae absent.

Tergum (Fig. 29c). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae, scales egg-shaped. Posterior margin of tergum IV with rounded spines, wider than long.

Gills (Fig. 29d). Present on segments II–VII. Margin with alternating smaller and bigger denticles intercalating long, 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 segments VIII and 2/3 IX combined.

Paraproct (Fig. 29e, f). Distally expanded, with many marginal, stout spines. Surface with U-shaped scale bases, scattered micropores and fine, simple setae and three robust, lanceolate setae near lateral margin. Postero-lateral extension (cercotractor) with small marginal spines.

Etymology.

Dedicated to Marion Podolak (Museum for Zoology Lausanne, MZL) for her valuable support during our study.

Distribution.

New Guinea.

Type-material.

Holotype. Nymph (on slide, GBIFCH 00465227), Papua New Guinea, Eastern Highlands, Aiyura, 1710 m, 15 Jan 2003, 06°21.41'S, 145°54.34'E, grassland stream, K. Sagata leg. Deposited in ZSM. Paratypes. 2 nymphs (1 on slide, GBIFCH 00465194, 1 in alcohol, GBIFCH 00515276, deposited in MZL), same data as holotype.