Labiobaetis lachicae, 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 lachicae sp. nov. Figures 11 , 12 , 42b , 47a , 48c

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of one plus 5-7 long, simple setae; B) labial palp segment II with a thumb-like distomedial protuberance, segment III conical; C) left mandible without setae at apex of mola; D) fore femur rather broad, length ca. 3 × maximum width, dorsal margin with 10-12 curved, spine-like setae and a partial second row near margin; E) claw with 15-17 denticles; F) paraproct distally not expanded, with ca. 13 stout, marginal spines.

Description.

Larva (Figs 11 , 12 , 42b , 47a ). Body length 3.6-3.7 mm. Cerci ca. 2/3 of body length. Paracercus ca. 2/3 of cerci length. Antenna approx. twice as long as head length.

Colouration. Head dorsally light brown, thorax and abdomen dorsally brown, with bright pattern as in Fig. 42b . Fore protoptera light brown with distinct brown striation. Head, thorax, and abdomen ventrally brown with bright pattern as in Fig. 47a . Legs ecru, femur with two partly merged distomedial brown spots, apex with brown spot, tibia with distomedial brown area. Caudalii light brown, with a brown band at ca. 1/3 of cerci, cerci brown in distal part.

Antenna (Fig. 12f ) with scape and pedicel subcylindrical, without distolateral process at scape.

Labrum (Fig. 11a ). 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 one plus 5-7 long, simple setae, the first two setae after the submedian seta are close together. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid setae; ventral surface with ca. six short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 11b, c ). Incisor and kinetodontium fused. Incisor with four 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 with a pronounced hump. Tuft of setae at apex of mola present and many thin setae distally at base of mola.

Left mandible (Fig. 11d, e ). Incisor and kinetodontium fused. Incisor with three denticles; kinetodontium with three denticles. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola 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 absent.

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

Hypopharynx and superlinguae (Fig. 11f ). Lingua shorter than superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, short; distal half laterally expanded. Superlinguae distally rounded; lateral margin angulate; fine, long, simple setae along distal margin.

Maxilla (Fig. 11g ). 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 four medium to long, simple setae. Maxillary palp 1.3 × as long as length of galea-lacinia; 2-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, without excavation at inner distolateral margin.

Labium (Fig. 11h, i ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ca. nine short, stout, spine-like setae plus distalmost one much longer, less robust, spine-like seta; apex with two long and one medium, robust, pectinate setae; outer margin with four 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 four medium, simple setae in anteromedial area; outer margin with some long, spine-like setae; dorsally with a row of five long, spine-like, simple setae near inner margin. Labial palp with segment I 0.9 × length of segments II and III combined. Segment I ventrally with short, fine, simple setae and one short, stout, simple seta at inner margin. Segment II with thumb-like distomedial protuberance; distomedial protuberance 0.8 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with a row of 6-8 medium, spine-like, simple setae near outer margin. Segment III conical; apex rounded; length 1.1 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 12g ) minute.

Foreleg (Fig. 12a, b ). Ratio of foreleg segments 1.4:1.0:0.8:0.3. Femur. Length ca. 3 × maximum width. Dorsal margin with 10-12 curved, spine-like setae, proximally and medially a partial second row of spine-like setae and some additional stout setae near margin; length of setae 0.23 × maximum width of femur. Apex rounded, with a pair of spine-like setae and some short, stout setae. Many stout, lanceolate setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin with a row of short to medium, spine-like setae, on apex one longer, spine-like seta. Ventral margin with a row of medium, curved, spine-like setae, distally of patellotibial suture one long, curved, spine-like seta, on apex some longer, partly bipectinate, spine-like setae and a tuft of fine, simple setae. Anterior surface scattered with stout, lanceolate setae. Patellotibial suture present on basal half. Tarsus. Dorsal margin with some short, stout setae. Ventral margin with a row of curved, spine-like setae and some spine-like setae near margin. Claw with one row of 15-17 denticles; distally pointed; with ca. six stripes; subapical setae absent.

Terga (Fig. 12c ). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae and micropores. Posterior margin of tergum IV with rounded, partly fused spines, wider than long.

Gills (Fig. 12d ). Present on segments II-VII. Margin with small denticles intercalating fine simple setae. Tracheae partly extending from main trunk towards outer and inner margins. Gill IV as long as length of segments V and VI combined. Gill VII as long as length of segments VIII and IX combined.

Paraproct (Fig. 12e ). Distally not expanded, with ca. 13 stout, marginal spines. Surface scattered with U-shaped scale bases, fine, simple setae and micropores. Cercotractor with small, marginal spines.

Etymology.

Dedicated to Ms. Maria Kenosis Lachica (Philippines/Japan), friend of the AdMU Biodiversity Laboratory.

Distribution.

Philippines: Mindanao (Fig. 48c ).

Biological aspects.

The specimens were collected at altitudes from sea level to 120 m, in root packs, grass bunches or submerged wood in riffles or runs.

Type material.

Holotype. Philippines • 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; GenBank: MT830950; GBIFCH 00654891; PNM. Paratypes. Philippines • 2 larvae; same data as holotype; 1 on slide; GBIFCH 00592269; AdMU; 1 on slide; GBIFCH 00592310; ZSM. Other material. Philippines • 1 larva; Mindanao, Surigao del Sur, Tandag, middle Tandag River; 30 m; 09°03'33"N, 126°05'57"E; 04.XII.2018; leg. Pangantihon; in alcohol; GBIFCH 00515332; AdMU • 1 larva; Mindanao, Surigao del Sur, Tandag, Pangi, Pangi River; 09°06'18"N, 126°08'53"E; 10 m; 30.XI.2018, leg. Pangantihon; on slide; GBIFCH 515520; ZSM.

Figures

Figure 11. Labiobaetis lachicae sp. nov., larva morphology a labrum b right mandible c right prostheca d left mandible e left prostheca f hypopharynx and superlinguae g maxilla h labium i apex of paraglossa.

Figure 12. Labiobaetis lachicae sp. nov., larva morphology a foreleg b fore claw c tergum IV d gill IV e paraproct f antennal scape g metanotum.

Figure 42. Habitus, larvae, dorsal view a Labiobaetis camiguinensis sp. nov. b Labiobaetis lachicae sp. nov. c Labiobaetis palawano sp. nov. d Labiobaetis sabordoi sp. nov.

Figure 47. Habitus, larvae, ventral view a Labiobaetis lachicae sp. nov. b Labiobaetis palawano sp. nov. c Labiobaetis sabordoi sp. nov. d Hypopharynx and superlinguae of Labiobaetis camiguinensis sp. nov.

Figure 48. Distribution of Labiobaetis in the Philippines a Philippines, overview b Group Labiobaetis dendrisetis c Group Labiobaetis numeratus.