Labiobaetis baganii, Kaltenbach & Garces & Gattolliat, 2020

Kaltenbach, Thomas, Garces, Jhoana M. & Gattolliat, Jean-Luc, 2020, The success story of Labiobaetis Novikova & Kluge in the Philippines (Ephemeroptera, Baetidae), with description of 18 new species, ZooKeys 1002, pp. 1-114 : 1

Labiobaetis baganii sp. nov. Figures 29 , 30 , 44c , 49b

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of 17-21 long, clavate setae; B) labial palp segment II with a thumb-like distomedial protuberance, segment III slightly pentagonal; C) left mandible without setae at apex of mola; D) fore femur rather slender, length ca. 4 × maximum width, dorsal margin with 8-11 curved, spine-like setae; E) paraproct distally expanded, with 39-43 stout, marginal spines.

Description.

Larva (Figs 29 , 30 , 44c ). Body length 3.1-5 mm. Cerci ca. 1/2 of body length. Paracercus: ca. 2/3 of cerci length. Antenna approx. twice as long as head length.

Colouration. Head, thorax, and abdomen dorsally brown, thorax with pattern as in Fig. 44c , fore protoptera brown. Head, thorax, and abdomen ventrally light brown. Legs light brown, femur with a brown distomedial spot connected to a brown streak along ventral margin, apex brown. Caudalii light brown.

Antenna (Fig. 30f ) with scape and pedicel subcylindrical, without distolateral process at scape.

Labrum (Fig. 29a, b ). Rectangular, length 0.7 × maximum width. Distal margin with medial emargination and a small process. Dorsally with medium to long, fine, simple setae scattered over surface; submarginal arc of setae composed of 17-21 long, clavate setae. Ventrally with marginal row of setae composed of anterolateral long, feathered setae and medial long, bifid setae; ventral surface with ca. five short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 29c, d ). 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 slightly convex, with minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 29e, f ). Incisor and kinetodontium fused. Incisor with five denticles; kinetodontium with three denticles. Prostheca robust, apically with small denticles and comb-shaped structure. 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 absent.

Both mandibles with lateral margins almost straight. Basal half with fine, simple setae scattered over dorsal surface.

Hypopharynx and superlinguae (Fig. 29g ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed; distal half laterally expanded. Superlinguae distally straight; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 29h ). 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 bipectinate, spine-like seta and three or four medium to long, simple setae. Maxillary palp 1.4 × as long as length of galea-lacinia; 2-segmented; palp segment II 1.5 × length of segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment rounded, with excavation at inner distolateral margin.

Labium (Fig. 29i ). 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 medium, robust, pectinate setae; outer margin with five spine-like setae increasing in length distally; 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 a row of three or four medium, simple setae in anteromedial area; dorsally with a row of four long, spine-like, simple 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 thumb-like distomedial protuberance; distomedial protuberance 0.7 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with two long, spine-like, simple setae near outer margin. Segment III slightly pentagonal; apex rounded; length 1.3 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera absent.

Foreleg (Fig. 30a, b ). Ratio of foreleg segments 1.1:1.0:0.4:0.1. Femur. Length ca. 4 × maximum width. Dorsal margin with 8-11 long, curved, spine-like setae; length of setae 0.24 × maximum width of femur. Apex rounded, with a pair of long, curved, spine-like setae and one or two short, stout setae. Many stout, lanceolate setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin with a row of short, spine-like setae, on apex one longer, spine-like seta. Ventral margin with a row of short, curved, spine-like setae, on apex some longer, 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 some fine, simple setae. Ventral margin with a row of curved, spine-like setae. Claw with one row of ten or eleven denticles; distally pointed; with ca. three stripes; subapical setae absent.

Terga (Fig. 30c ). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae. Posterior margin of tergum IV with triangular spines, wider than long.

Gills (Fig. 30d ). 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 half VI combined. Gill VII little longer than length of segment VIII.

Paraproct (Fig. 30e ). Distally expanded, with 39-43 stout, marginal spines. Surface scattered with U-shaped scale bases, fine, simple setae and micropores. Cercotractor with numerous small, marginal spines.

Etymology.

Dedicated to Mr. Bagani Sularte (Philippines), outstanding illustrator and friend of one of the authors (JG), for support in her dissertation work.

Distribution.

Philippines: Mindanao and Camiguin (Fig. 49b ).

Biological aspects.

The specimens were collected at altitudes from sea level to 660 m, mainly in submerged wood or leaf packs in the runs.

Type material.

Holotype. Philippines • larva; Mindanao, Agusan N, Cabadbaran River; 09°10'15"N, 125°40'55"E; 240 m.; 03.VI.2018; leg. Freitag and Pangantihon; on slide; GenBank: MT830974; GBIFCH 00654895; PNM. Paratypes. Philippines • 2 larvae; same data as holotype; 1 on slide; GBIFCH 00592303; ZSM; 1 in alcohol; GBIFCH 00515483; AdMU • 1 larva; Mindanao, Agusan del Sur, San Francisco, Bayogan, Tagkunayan Creek; 08°28'N, 125°59'E; 120 m; 05.II.1998; leg. Mendoza; on slide; GBIFCH 00592317; AdMU • 1 larva; Mindanao, Agusan del Norte, Jabonga, Creek upstream of village near Mainit; 09°20'40"N, 125°30'50"E; 50 m; 02.IV.2019, leg. Freitag; in alcohol; GBIFCH 00515484; ZSM • 1 larva; Mindanao, Agusan N, Cabadbaran, Del Pilar, Payas River; 09°11'34"N, 125°36'34"E; 660 m; 23.VI.2018; leg. Pangantihon; in alcohol; GBIFCH 00515485; ZSM • 15 larvae; Camiguin, Sagay, Bonbon, lower Binangawan River; 09°06'39"N 124°43'45"E; 30 m; 09.XII.2018; leg. Freitag and Wantzen; 2 on slides; GenBank: MT830975; GBIFCH 00654899, GBIFCH 592326; ZSM; 2 in alcohol; GBIFCH 00515486, GBIFCH 00515488; AdMU; 11 in alcohol; GBIFCH 515487; AdMU.

Figures

Figure 29. Labiobaetis baganii sp. nov., larva morphology a labrum b seta of arc on dorsal surface of labrum c right mandible d right prostheca e left mandible f left prostheca g hypopharynx and superlinguae h maxilla i labium.

Figure 30. Labiobaetis baganii sp. nov., larva morphology a foreleg b fore claw c tergum IV d gill IV e paraproct f antennal scape.

Figure 44. Habitus, larvae, dorsal view a Labiobaetis valdezorum sp. nov. b Labiobaetis wantzeni sp. nov. c Labiobaetis baganii sp. nov. d Labiobaetis delocadoi sp. nov.

Figure 49. Distribution of Labiobaetis in the Philippines a Group Labiobaetis operosus b Group Labiobaetis sumigarensis c Group Labiobaetis vallus.