Labiobaetis roulade, Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2019

Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2019, The tremendous diversity of Labiobaetis Novikova & Kluge in Indonesia (Ephemeroptera, Baetidae), ZooKeys 895, pp. 1-117 : 1

5. Labiobaetis roulade sp. nov. Figures 9 , 10 , 47d , 52c , 55a

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of 1 + 8-9 feathered setae; B) maxillary palp approx. as long as galea-lacinia; C) labial palp segment II with broad thumb-like distomedial protuberance, segment III conical; D) fore femur rather slender, length 3.7 × maximum width, dorsal margin with ca. 15 spine-like setae, apically rounded and with minute serration; E) paraproct distally not expanded, with ca. 21 stout marginal spines.

Description.

Larva ( Figs 9 , 10 , 47d , 52c ). Body length 5.2-6.2 mm. Cerci ca. 1/2 of body length. Antenna approximately 2.5 × as long as head length.

Colouration. Head, thorax, and abdomen dorsally brown, head and thorax with bright median, dorsal suture, thorax and abdomen with bright pattern as in Fig. 47d , forewing pads with bright striation. Head, thorax, and abdomen ventrally brown, legs transparent, femur ventrodistomedially and distally with brown spot and dorsally with brown streak along margin ( Fig. 52c ), caudal filaments transparent with brown band at 1/3 of cerci.

Antenna with scape and pedicel subcylindrical, with well-developed distolateral process at scape; flagellum with broad, apically blunt spines and fine, simple setae on apex of each segment.

Labrum ( Fig. 9a ). 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 1 + 8-9 feathered setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with four short, spine-like setae near lateral and anterolateral margin.

Right mandible ( Fig. 9b, 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 slightly convex. Tuft of setae at apex of mola present.

Left mandible ( Fig. 9d, e ). Incisors fused. Outer and inner sets of denticles with 4 + 3 denticles and one minute intermediate denticle. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola slightly convex. 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 and slightly lanceolate setae scattered over surface.

Hypopharynx ( Fig. 9f ). Lingua longer than superlingua. Lingua longer than broad; medial tuft of stout setae poorly developed; distal half laterally expanded. Superlingua rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla ( Fig. 9g ). 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 five long, simple setae. Maxillary palp approx. as long as length of galea-lacinia; two segmented; palp segment II 1.6 × length of segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment slightly pointed, with excavation at inner distolateral margin.

Labium ( Fig. 9h ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with nine spine-like setae increasing in length distally; apex with two long and one medium, robust, pectinate setae; outer margin with seven spine-like setae increasing in length distally; ventral surface with short, fine, simple and short, spine-like setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and 2-3 medium, simple setae in anteromedial 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 broad thumb-like distomedial protuberance; distomedial protuberance 0.5 × width of base of segment III; inner and outer margin with short, fine, simple setae; dorsally with a row of four long, spine-like, simple setae near outer margin. Segment III conical; apex slightly pointed; length 0.8 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg ( Fig. 10 a–f ). Ratio of foreleg segments 1.3:1.0:0.6:0.2. Femur. Length ca. 4 × maximum width. Dorsal margin with a row of ca. 15 curved, spine-like setae, apically rounded and with minute serration, and many fine, simple setae; length of setae 0.17 × maximum width of femur. Apex rounded; with one pair of curved, spine-like setae, apically rounded and with minute serration, and some short, stout setae. Short, stout, lanceolate setae scattered along the ventral margin; femoral patch reduced to a few setae. Tibia. Dorsal margin with a row of short, lanceolate, apically rounded setae and many short, lanceolate, apically rounded setae scattered along the dorsal margin. Ventral margin with a row of short, curved, spine-like setae, on apex some spine-like, partly bipectinate 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, lanceolate, apically rounded setae and many short, lanceolate, apically rounded setae scattered along the dorsal margin. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of 15 denticles; distally pointed; with 7-8 stripes; subapical setae absent.

Tergum ( Fig. 10g ). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae and micropores. Posterior margin of tergum IV with rounded or triangular spines, wider than long.

Gills ( Fig. 10h ). Present on segments I–VII. Margin with small denticles intercalating fine simple setae. Tracheae partly extending from main trunk towards outer and inner margins. Gill I ca. 2/3 length of segment II. Gill IV as long as length of segments V and 2/3 VI combined. Gill VII as long as length of segments VIII and 1/3 IX combined.

Paraproct ( Fig. 10i ). Distally not expanded, with ca. 21 stout marginal spines. Surface scattered with U-shaped scale bases, fine, simple setae and micropores. Cercotractor with numerous small marginal spines.

Etymology.

Dedicated to Jean-Marc Elouard, the collector of the specimens and well-known ephemerologist. The name is an anagram of Elouard.

Distribution.

Indonesia: Sumatra.

Biological aspects.

The specimens were collected at an altitude of 530 m.

Type-material.

Holotype. Larva (on slide, GBIFCH 00592234), Indonesia, Sumatra Barat, Payakumbuh, south of Payakumbuh, 00°16.55'S, 100°36.28'E, 530 m, 28.V.2010, J.-M. Elouard leg. Temporary deposited in MZL before definitely housed in MZB. Paratypes. 9 larvae (2 on slides, GBIFCH 00592235, GBIFCH 00592250, 4 in alcohol, GBIFCH 00515364, deposited in MZL; 3 in alcohol, GBIFCH 00515363, GBIFCH 00657757, GBIFCH 00657756, deposited in ZSM), same data as holotype.

Figures

Figure 9. Labiobaetis roulade sp. nov., larva morphology: a Labrum b Right mandible c Right prostheca d Left mandible e Left prostheca f Hypopharynx g Maxilla h Labium.

Figure 10. Labiobaetis roulade sp. nov., larva morphology: a Foreleg b Femur dorsal seta c Femur ventral seta d Tibia dorsal seta e Femur dorsal margin f Fore claw g Tergum IV h Gill IV i Paraproct j Scape k Metanotum.

Figure 47. Habitus, larvae, dorsal view: a Labiobaetis batakorum sp. nov. b Labiobaetis sulawesiensis sp. nov. c Labiobaetis sumbensis sp. nov. d Labiobaetis roulade sp. nov.

Figure 52. Larvae: a Labiobaetis batakorum sp. nov., ventral view, legs b Labiobaetis sumbensis sp. nov., ventral view, legs c Labiobaetis roulade sp. nov., ventral view, legs d Labiobaetis weifangae sp. nov., ventral view, legs e Labiobaetis gueuningi sp. nov., ventral view f Labiobaetis jonasi sp. nov., ventral view.

Figure 55. Distribution of Labiobaetis in Indonesia.