Labiobaetis wahai, 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

23. Labiobaetis wahai sp. nov. Figures 40 , 41 , 50d , 54b

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of 1 + 5 long, simple setae; B) labial palp segment II with thumb-like distomedial protuberance; C) maxillary palp approx. as long as length of galea-lacinia; D) fore femur rather slender, length 3.6 × maximum width, dorsal margin with a row of ca. 22 curved, spine-like setae, an additional row of spine-like setae along margin; E) posterior margin of tergum IV with triangular spines, longer than wide; F) paraproct distally expanded, with ca. 47 stout marginal spines.

Description.

Larva ( Figs 40 , 41 , 50d ). Body length 5.5 mm.

Colouration. Head, thorax, and abdomen dorsally brown, head and thorax with bright median, dorsal suture. Head, thorax, and abdomen ventrally light brown, legs light brown with distomedial, brown streak on femur, caudal filaments light brown.

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

Labrum ( Fig. 40a ). 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 1 + 5 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 seven short, spine-like setae near lateral and anterolateral margin.

Right mandible ( Fig. 40b, c ). Incisors fused. Outer and inner sets of denticles with 4 + 4 denticles and 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. 40d, e ). Incisors fused. Outer and inner sets of denticles with 4 + 3 denticles. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola slightly convex, with minute denticles toward 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. 40f ). Lingua approx. as long as superlingua. Lingua approx. as broad as long; medial tuft of stout setae well developed, short; distal half not expanded. Superlingua rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla ( Fig. 40g ). 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 six long, simple setae. Maxillary palp approx. as long as length of galea-lacinia; two 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 slightly pointed, without excavation at inner distolateral margin.

Labium ( Fig. 40h, i ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with eight spine-like setae increasing in length distally; apex with two long and one medium, robust, pectinate setae and one short, robust seta; outer margin with 6-8 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 three medium, simple setae in anteromedial area and one fine, simple seta in proximomedial area; dorsally with a row of five 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 and medium, fine, simple setae. Segment II with thumb-like distomedial protuberance; distomedial protuberance 0.6 × width of base of segment III; inner and outer margin with short, fine, simple setae; dorsally with a row of four medium, spine-like setae near outer margin. Segment III approx. semi-circular; apex rounded; length 0.9 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg ( Fig. 41a, b ). Ratio of foreleg segments 1.1:1.0:0.4:0.2. Femur. Length ca. 4 × maximum width. Dorsal margin with Dorsal margin with a row of ca. 22 curved, spine-like setae and a row of spine-like setae along margin; length of setae 0.11 × maximum width of femur. Apex rounded; with one pair of spine-like setae and some shorter, stout setae. Many stout, lanceolate setae scattered along the ventral margin; femoral patch absent. Tibia. Dorsal margin with a row of stout, lanceolate setae and many stout, lanceolate setae scattered along the margin. Ventral margin with a row of curved, spine-like setae, on apex some stout, spine-like, partly bipectinate setae and a tuft of fine, simple setae. Anterior surface scattered with stout, lanceolate setae. Patellotibial suture present on basal 1/3. Tarsus. Dorsal margin with a row of short, spine-like setae. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of ten denticles; distally pointed; with five stripes; subapical setae absent.

Tergum ( Fig. 41c ). 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. 41d ). Present on segments II–VII. Margin with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Gill VII as long as length of segments VIII and 1/3 IX combined.

Paraproct ( Fig. 41e ). Distally expanded, with> 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 Wahai people from Seram.

Distribution.

Indonesia: Seram.

Biological aspects.

The specimens were collected at an altitude of 600 m.

Type-material.

Holotype. Larva (on slide, GBIFCH 00592208), Indonesia, Maluku, Seram, Kanikeh, 607 m, 07.IV.2012, 03°06.52'S, 129°28.80'E, M. Balke leg. (AMB07). Temporary deposited in MZL before definitely housed in MZB. Paratype. Larva (on slide, GBIFCH 00592209, deposited in MZL), same data as holotype.

Figures

Figure 40. Labiobaetis wahai sp. nov., larva morphology: a Labrum b Right mandible c Right prostheca d Left mandible e Left prostheca f Hypopharynx g Maxilla h Labium i Apex of paraglossa.

Figure 41. Labiobaetis wahai sp. nov., larva morphology: a Foreleg b Fore claw c Tergum IV d Gill IV e Paraproct.

Figure 50. Habitus, larvae, dorsal view: a Labiobaetis paranumeratus sp. nov. b Labiobaetis pilosus sp. nov. c Labiobaetis seramensis sp. nov. d Labiobaetis wahai sp. nov.

Figure 54. Distribution of Labiobaetis in Indonesia.