Labiobaetis aldabae, 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 aldabae sp. nov. Figures 7 , 8 , 41c , 46b , 48c

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of 4-6 long, simple setae; B) labial palp segment II with a thumb-like distomedial protuberance, segment III conical; C) left mandible with a comb-shaped structure at base of mola; D) fore femur rather broad, length 3.4 × maximum width, with ca. nine curved, spine-like setae and a partial second row near margin; E) claw with 12-15 denticles; F) paraproct distally not expanded, with 18-21 stout, marginal spines.

Description.

Larva (Figs 7 , 8 , 41c , 46b ). Body length 4.1-5.4 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. 41c . Fore protoptera light brown with darker and brighter striation. Head, thorax, and abdomen ventrally brown with bright pattern as in Fig. 46b . Femur with a distomedial brown spot and a distodorsal brown streak, apically brown, tibia partially light brown, tarsus light brown, apically darker. Caudalii light brown with a brown dark band at ca. 1/3 of cerci length, distal area of cerci brown.

Antenna (Fig. 8f ) with scape and pedicel subcylindrical, without distolateral process at scape.

Labrum (Fig. 7a ). 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 4-6 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, pectinate setae; ventral surface with ca. five short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 7b, 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. 7d-f ). 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 present. Comb-shaped structure at base of mola present.

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

Hypopharynx and superlinguae (Fig. 7g ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, short; distal half not expanded. Superlinguae distally rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 7h ). 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 1.6 × 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. 7i ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ca. ten 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 five long, 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 two or three medium, simple setae in anteromedial area; outer margin with some long, spine-like setae; 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 a row of six or seven long, spine-like, simple setae near outer margin. Segment III conical; apex slightly truncate; length 1.3 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 8g ) minute.

Foreleg (Fig. 8a, b ). Ratio of foreleg segments 1.3:1.0:0.7:0.3. Femur. Length ca. 3 × maximum width. Dorsal margin with a row of ca. nine curved, spine-like setae, a partial row of spine-like setae near margin; length of setae 0.19 × maximum width of femur. Apex rounded, with a pair of curved, 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, spine-like setae and fine, simple setae, on apex one longer, spine-like seta. Ventral margin with a row of short to medium curved, spine-like setae, distally of patellotibial suture one longer, 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 a row of fine, simple setae. Ventral margin with a row of curved, spine-like setae. Claw with one row of 12-15 denticles on Luzon Island and ca. 17 denticles on Negros Island; distally pointed; with 4-7 stripes; subapical setae absent.

Terga (Fig. 8c ). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae. Posterior margin of tergum IV with rounded, partly fused spines, wider than long.

Gills (Fig. 8d ). 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 3/4 VI combined. Gill VII as long as length of segments VIII and ½ IX combined.

Paraproct (Fig. 8e ). Distally not expanded, with 18-21 stout, marginal spines. Surface scattered with U-shaped scale bases and fine, simple setae. Cercotractor with numerous small, marginal spines.

Etymology.

Dedicated to Ms. Kyra Mari Dominique Aldaba (Philippines), member of the AdMU Biodiversity Laboratory.

Distribution.

Philippines: Luzon and Negros (Fig. 48c ).

Biological aspects.

The specimens were collected at altitudes from 50 m to 1400 m, mainly in riverside pools, but also in root packs or grass bunches in the runs.

Type material.

Holotype. Philippines • larva; Luzon, Laguna, Samil River; 14°08'N, 121°31'E; 370 m; 27.VI.2018; leg. BIO-PHIL exped.; on slide; GenBank: MT830944; GBIFCH 00654913; PNM. Paratypes. Philippines • 2 larvae; same data as holotype; 1 on slide; GBIFCH 00592273; ZSM; 1 in alcohol, GBIFCH 00515409; ZSM • 1 larva; Luzon, Nueva Ecija, Pantabangan, Candaclan River; 240 m, 15°46'48"N, 121°13'17"E; 240 m; 05.II.1998; leg. Mendoza; on slide; GenBank: MT830945; GBIFCH 00654908; ZSM • 39 larvae; Luzon, Benguet, Tuba, Taloy Sur; 16°21'33"N, 120°30'31"E; 400 m; XI.1997; leg. Mey; 1 on slide; GenBank: MT830947; GBIFCH 00763648; AdMU; 38 in alcohol; GBIFCH 00515443; ZSM • 126 larvae; Luzon, Benguet, Kabayan, Bongis Bridge; 16°34'11"N, 120°50'12"E; 1000 m; XI.1997; leg. Mey; 1 on slide; GenBank: MT830946; GBIFCH 00763646; AdMU; 66 in alcohol; GBIFCH 00515440; 59 in alcohol; GBIFCH 00515500, GBIFCH 00515464, GBIFCH 00515441; ZSM • 1 larva; Negros Oriental, Valencia, Malaunay, small river; 09°18'17"N, 123°10'07"E; 470 m; 01.IX.2019; leg. Garces and Pelingen; on slide; GenBank: MT830948; GBIFCH 00654889; ZSM.

Other material.

Philippines • 27 larvae; Luzon, Ifugao, Tinoc; 16°40'58"N, 120°56'59"E; 1400 m; XI.1997; leg. Mey; in alcohol; GBIFCH 00515444; AdMU • 4 larvae; Luzon, Ilocos Sur, Suyo Municipality, Tagudin-Cervantes-Sabangan Road, Besang Pass Area; 16°57'17"N, 120°38'52"E; 1200 m; 15.IV.2019; leg. Freitag, Garces and Pangantihon; in alcohol; GBIFCH 00515442; ZSM.

Figures

Figure 7. Labiobaetis aldabae sp. nov., larva morphology a labrum b right mandible c right prostheca d left mandible e left prostheca f comb-shaped structure at left mola g hypopharynx and superlinguae h maxilla i labium.

Figure 8. Labiobaetis aldabae sp. nov., larva morphology a foreleg b fore claw c tergum IV d gill IV e paraproct f antennal scape g metanotum.

Figure 41. Habitus, larvae, dorsal view a Labiobaetis dalisay sp. nov. b Labiobaetis acei sp. nov. c Labiobaetis aldabae sp. nov.

Figure 46. Habitus, larvae, ventral view a Labiobaetis acei sp. nov. b Labiobaetis aldabae sp. nov. c Labiobaetis camiguinensis sp. nov.

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