Labiobaetis valdezorum, 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 valdezorum sp. nov. Figures 23 , 24 , 44a , 49a

Diagnosis.

Larva. Following combination of characters: A) dorsal surface of labrum with submarginal arc of one plus 9-12 feathered setae; B) labial palp segment II with broad, thumb-like distomedial protuberance; C) fore femur rather broad, length ca. 3 × maximum width, dorsal margin with 12-15 curved, spine-like setae, fore tarsus broad with dorsal and ventral margins slightly convex; D) claw with eleven or twelve denticles; E) paraproct distally not expanded, with 23-32 stout marginal spines and some additional submarginal spines.

Description.

Larva (Figs 23 , 24 , 44a ). Body length 5.5-5.9 mm. Cerci ca. 2/3 of body length. Paracercus ca. 2/3 of cerci length. Antenna approx. 2.5 × as long as head length.

Colouration. Head, thorax, and abdomen dorsally light brown, with darker pattern as in Fig. 44a , abdominal segments VIII and IX dark brown. Fore protoptera light brown, basally darker, with bright striation. Head, thorax, and abdomen ventrally light brown, frons and genae darker brown, abdominal segments VIII and IX dark brown. Legs light brown, femur with distomedial dark brown spot, apically brown, tarsus dorsodistally dark brown. Caudalii light brown with a dark brown band at ca. 1/3 of cerci length.

Antenna (Fig. 24f ) with scape and pedicel subcylindrical, with well-developed distolateral process at scape.

Labrum (Fig. 23a ). Rectangular, length 0.8 × 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 9-12 long, feathered setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with ca. eight short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 23b, c ). 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. Tuft of setae at apex of mola present.

Left mandible (Fig. 23d, e ). Incisor and kinetodontium fused. Incisor with four denticles; kinetodontium with three 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 and superlinguae (Fig. 23f ). 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 rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 23g ). 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 five medium to long, simple setae. Maxillary palp slightly longer than length of galea-lacinia; 2-segmented; palp segment II 1.4 × length of segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment rounded, with slight excavation at inner distolateral margin.

Labium (Fig. 23h ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ca. ten 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 eight long, spine-like setae; ventral surface with short, fine, simple and short, spine-like setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and one medium, simple seta in anteromedial area; dorsally with a row of six or seven 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 broad thumb-like distomedial protuberance; distomedial protuberance 0.6 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with a row of three or four spine-like, simple setae near outer margin. Segment III conical; apex slightly pointed; length subequal to width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 24g ) well developed.

Foreleg (Fig. 24a, b ). Ratio of foreleg segments 1.2:1.0:0.6:0.2. Femur. Length ca. 3 × maximum width. Dorsal margin with a row of 12-15 curved, spine-like setae, sometimes a few additional setae near margin in basal area; length of setae 0.14 × 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, spine-like setae, on apex one longer, spine-like seta. Ventral margin with a row of mainly short, spine-like setae, on apex some longer and partly bipectinate 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 short, stout setae. Ventral margin with a row of curved, spine-like setae and in distal area fine simple setae. Claw with one row of eleven or twelve denticles; with ca. six stripes; subapical setae absent.

Terga (Fig. 24c ). 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. 24d ). Present on segments I-VII. Margin with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Gill I as long as length of segment II. Gill IV as long as length of segments V and half of VI combined. Gill VII as long as length of segment VIII.

Paraproct (Fig. 24e ). Distally not expanded, with 23-32 stout, marginal spines and some submarginal spines. Surface scattered with U-shaped scale bases and fine, simple setae. Cercotractor with numerous small, marginal spines, apically pointed.

Etymology.

Dedicated to Dr. Emma Aguada Valdez, Mr. Rolando Valdez and Mr. Francis Paolo Valdez for their generous help and support in the scientific projects of the AdMU Biodiversity Laboratory.

Distribution.

Philippines: Negros and Cebu (Fig. 49a ).

Biological aspects.

The specimens were collected at altitudes from 150 m to 480 m, on bottom gravel or submerged wood in runs or riffles.

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; GenBank. MT830963; GBIFCH 00654888; PNM. Paratypes. Philippines • 24 larvae; same data as holotype; 3 on slides; GenBank. MT830965, MT830966; GBIFCH 00654879, GBIFCH 00592277, GBIFCH 00654880; ZSM; 1 on slide; GenBank: MT830964; GBIFCH 00654882; AdMU; 7 in alcohol; GBIFCH 00515419; ZSM; 13 in alcohol; GBIFCH 00515418, GBIFCH 00515420; AdMU • 1 larva; Negros Oriental, Valencia, Apolong, Casaroro River upstream; 09°17'N, 123°13'E; 470 m; 01.IX.2019; leg. Garces and Pelingen; in alcohol; GBIFCH 00515421; ZSM • 15 larvae; Cebu, Cebu City, Lusaran; 10°28'13"N, 123°52'26"E; 200 m; 16.IX.1996; leg. Mendoza; 1 on slide; GenBank: MT830967; GBIFCH 00763671; ZSM; 10 in alcohol; GBIFCH 00515422, GBIFCH 00515423, GBIFCH 00515424; AdMU; 4 in alcohol; GBIFCH 00515425; ZSM.

Figures

Figure 23. Labiobaetis valdezorum 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 24. Labiobaetis valdezorum sp. nov., larva morphology a foreleg b fore claw c tergum IV d gill IV e paraproct f antennal scape g metanotum.

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.