Labiobaetis sabordoi, 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 sabordoi sp. nov. Figures 15 , 16 , 42d , 47c , 48c

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of one plus five or six long, simple setae; B) labial palp segment II with a thumb-like distomedial protuberance, segment III conical; C) mola of right mandible proximally beginning with a double hump; D) hypopharynx with medial tuft of stout setae poorly developed; E) fore femur rather broad, length ca. 3 × maximum width, dorsal margin with 11-14 curved, spine-like setae and a partial second row near margin; F) claw with 16-18 denticles; G) posterior margin of tergum IV with triangular spines, wider than long.

Description.

Larva (Figs 15 , 16 , 42d , 47c ). Body length 3-3.5 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 with brown markings, thorax and abdomen dorsally brown with bright pattern as in Fig. 42d . Fore protoptera light brown with distinct brown striation. Head, thorax, and abdomen ventrally brown with bright pattern as in Fig. 47c . Legs light brown, femur with two connected brown spots, apically brown. Caudalii light brown, with a brown band at ca. 1/3 of cerci length, distal area of cerci brown.

Antenna (Fig. 16f ) with scape and pedicel subcylindrical, without distolateral process at scape.

Labrum (Fig. 15a ). 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 five or six 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. 15b, 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, mola proximally beginning with a double hump. Tuft of setae at apex of mola present and many thin setae distally at base of mola.

Left mandible (Fig. 15d, 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 and partly with minute secondary dentation at the tips. 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 and superlinguae (Fig. 15f ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae poorly developed; distal half laterally expanded. Superlinguae distally straight; lateral margin angulate; fine, long, simple setae along distal margin.

Maxilla (Fig. 15g ). 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 1.7 × 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. 15h ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ca. eight 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 and one short, robust seta; 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 four 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 0.9 × length of segments II and III combined. Segment I ventrally with short, fine, simple setae and one or two short, stout, simple setae at inner margin. 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 five or six medium, spine-like, simple setae near outer margin. Segment III conical; apex slightly truncate; length 1.2 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 16g ) minute.

Foreleg (Fig. 16a, b ). Ratio of foreleg segments 1.4:1.0:0.8:0.3. Femur. Length ca. 3 × maximum width. Dorsal margin with a row of 11-14 curved, spine-like setae in different length, proximally and medially a partial second row of spine-like setae near margin; length of setae 0.22 × 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, on apex one longer, spine-like seta. Ventral margin with a row of short to long, 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 and some fine, simple setae. Ventral margin with a row of curved, spine-like setae and some spine-like setae near margin. Claw with one row of 16-18 denticles; distally pointed; with ca. four stripes; subapical setae absent.

Terga (Fig. 16c ). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae. Posterior margin of tergum IV with triangular, partly fused spines, wider than long, sometimes apically rounded.

Gills (Fig. 16d ). 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. 16e ). Distally not expanded, with 13-23 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. Marc Ryan Sabordo (Philippines), collector and project assistant of the AdMU Biodiversity Laboratory.

Distribution.

Philippines: Negros, Sibuyan and Tablas (Fig. 48c ).

Biological aspects.

The specimens were collected at altitudes from sea level to 480 m, partly in leaf litter.

Type material.

Holotype. Philippines • larva; Negros Oriental, Valencia, Casaroro River downstream; 09°18'N, 123°14'E; 150 m; 01.IX.2019; leg. Garces and Pelingen; on slide; GBIFCH 00592270; PNM. Paratypes. Philippines • 1 larva; same data as holotype; on slide; GenBank: MT830951; GBIFCH 00654878; ZSM • 2 larvae; Romblon, Tablas, S of San Agustin; 12°33'38"N, 122°07'19"E; 40 m; 14.I.2019; leg. Freitag; 1 on slide; GenBank: MT830952; GBIFCH 00 763674; ZSM; 1 in alcohol; GBIFCH 00515334; ZSM • 2 larvae; Romblon, Sibuyan, Cajidiocan, Cambijang; 12°20'40"N, 122°40'37"E; 5 m; 16.I.2019; leg. Freitag; in alcohol; GBIFCH 00515333; AdMU.

Figures

Figure 15. Labiobaetis sabordoi 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.

Figure 16. Labiobaetis sabordoi 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.