First contribution to Labiobaetis Novikova & Kluge in Cambodia (Ephemeroptera, Baetidae), with description of two new species Author Kaltenbach, Thomas https://orcid.org/0000-0001-8052-0388 Museum of Zoology, Palais de Rumine, Place Riponne 6, CH- 1005 Lausanne, Switzerland & University of Lausanne (UNIL), Department of Ecology and Evolution, CH- 1015 Lausanne, Switzerland thomas.kaltenbach@bluewin.ch Author Garces, Jhoana https://orcid.org/0000-0001-5150-0281 Ateneo Biodiversity Research Laboratory, Department of Biology, School of Science and Engineering, Ateneo de Manila University, Quezon City, 1108 Metro Manila, Philippines Author Gattolliat, Jean-Luc https://orcid.org/0000-0001-5873-5083 Museum of Zoology, Palais de Rumine, Place Riponne 6, CH- 1005 Lausanne, Switzerland & University of Lausanne (UNIL), Department of Ecology and Evolution, CH- 1015 Lausanne, Switzerland text ZooKeys 2022 2022-10-04 1123 63 81 http://dx.doi.org/10.3897/zookeys.1123.90308 journal article http://dx.doi.org/10.3897/zookeys.1123.90308 1313-2970-1123-63 13556B2ABE8744F69A43FCDAFE1C68CB 1BCB0D62026158E7B962D3F2EE741FB4 Labiobaetis kui sp. nov. Figs 3 , 4 , 5c, d , 6b Diagnosis. Larva. Following combination of characters: A) antennal scape without process (Fig. 4g ); B) dorsal surface of labrum with submarginal arc of 16-18 long, clavate setae (Fig. 3a ); C) labial palp segment II with an extended, slightly hooked, thumb-like distomedial protuberance (Fig. 3i ); D) left mandible without setae at apex of mola (Fig. 3e ); E) fore femur rather slender, length ca 4 x maximum width, dorsal margin with 10-15 curved, spine-like setae (Fig. 4a ); F) hind protoptera absent; G) six pairs of terga-lii; H) paraproct distally slightly expanded, with 33-38 stout, marginal spines (Fig. 4f ). Figure 3. Labiobaetis kui sp. nov., larva morphology a labrum (left: ventral view, right: dorsal view) b seta of submarginal arc c right mandible d right prostheca e left mandible f left prostheca g hypopharynx and superlinguae h maxilla i labium (left: ventral view, right: dorsal view). Figure 4. Labiobaetis kui sp. nov., larva morphology a foreleg b seta of tibia dorsal margin c fore claw d tergum IV e tergalius IV f paraproct g antennal base. Description. Larva (Figs 3 , 4 , 5c, d ). Body length ca 4.9 mm. Caudalii broken. Antenna broken. Colouration (Fig. 5c, d ). Head, thorax, and abdomen dorsally uniform brown. Head, thorax, and abdomen ventrally light brown. Legs light brown; femur with a brown medial spot, darker on ventral margin, dorsal margin and apex brown. Caudalii light brown. Figure 5. Habitus, larvae a Labiobaetis brao sp. nov., dorsal view b Labiobaetis brao sp. nov., ventral view c Labiobaetis kui sp. nov., dorsal view d Labiobaetis kui sp. nov., ventral view. Scale bar: 1 mm. Antenna (Fig. 4g ) with scape and pedicel subcylindrical, without distolateral process at scape. Labrum (Fig. 3a, b ). Rectangular, length 0.7 x 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 16-18 long, clavate setae. Ventrally with marginal row of setae composed of anterolateral long, feathered setae and medial long, bifid setae; ventral surface with ca three short, spine-like setae near lateral and anterolateral margin. Right mandible (Fig. 3c, 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. Tuft of setae at apex of mola present. Left mandible (Fig. 3e, 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. 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. 3g ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed; distal half laterally expanded. Superlinguae distally almost straight; lateral margin rounded; fine, long, simple setae along distal margin. Maxilla (Fig. 3h ). 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. Medially with one pectinate, spine-like seta and three or four medium, simple setae. Maxillary palp 1.2 x as long as length of galea-lacinia; 2-segmented; palp segment II 1.2 x 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. 3i ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ca six spine-like setae increasing in length distally; apex with two long and one medium, robust, pectinate setae; outer margin with ca four spine-like setae; ventral surface with fine, simple, scattered setae. Paraglossa subrectangular, curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and a row of 2-4 medium, simple setae in anteromedial area; dorsally with a row of four or five long, spine-like, simple setae near inner margin. Labial palp with segment I 0.8 x length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II with extended, slightly hooked, thumb-like distomedial protuberance; distomedial protuberance 0.7 x 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, inner apical margin slightly concave; length subequal to width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae. Hind protoptera absent. Foreleg (Fig. 4a-c ). Ratio of foreleg segments 1.3:1.0:0.4:0.2. Femur . Length ca 4 x maximum width. Dorsal margin with 10-15 long, curved, spine-like setae; length of setae 0.23 x maximum width of femur. Apex rounded, with a pair of long, curved, spine-like setae and some short, stout setae. Many stout, lanceolate setae scattered along ventral margin; femoral patch absent. Tibia . Dorsal margin with row of short, stout, apically rounded setae, on apex one longer, spine-like seta. Ventral margin with row of short, curved, spine-like setae, on apex some longer setae and a tuft of fine, simple setae. Anterior surface scattered with stout, lanceolate setae near ventral margin. Patellatibial suture present on basal 1/3 area. Tarsus . Dorsal margin with some fine, simple setae. Ventral margin with row of curved, spine-like setae. Claw with one row of nine or ten denticles; distally pointed; with ca. five stripes; subapical setae absent. Terga (Fig. 4d ). 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. Tergalii (Fig. 4e ). Present on segments II-VII. Margins with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Tergalius IV as long as length of segments V and 1/3 VI combined. Tergalius VII as long as length of segment VIII. Paraproct (Fig. 4f ). Distally slightly expanded, with 33-38 stout, marginal spines. Surface scattered with U-shaped scale bases, fine, simple setae and micropores. Cercotractor with numerous small, marginal spines. Etymology. The new species is dedicated to the indigenous Kui people from northeastern Cambodia. Distribution. Cambodia (Fig. 6b ). Figure 6. Distribution of Labiobaetis in Cambodia a overview map b Labiobaetis species. Biological aspects. The specimens were collected from 100 m to 640 m, mostly on littoral gravel. Type material. Holotype . Cambodia • larva; Kampong Speu Province, Chambok River, 1.83 Km from Chambok Community; 240 m; 11°21'58"N , 104°06'17"E ; 11.07.2018; leg. H. Freitag and J. Garces; on slide; GBIFCH00592702; MZL. Paratypes . Cambodia • 14 larvae; same data as holotype; 1 on slide; GBIFCH00592701; MZL; 13 in alcohol; GenBank ON982737, ON982738; GBIFCH00515681, GBIFCH00829876, GBIFCH00829877, GBIFCH00975577, GBIFCH00975578; MZL • 7 larvae; Kampong Speu Province, waterfall at Kirirom National Park; 640 m; 11°20'26"N , 104°02'14"E ; 13.07.2018; leg. H. Freitag and J. Garces; 1 on slide; GBIFCH00592698; RUPP; 6 in alcohol; GBIFCH00975579; MZL • 1 larva; Kampong Speu Province, Kokie waterfall, secondary forest remnants; 110 m; 11°12'11"N , 104°03'49"E ; 12.07.2018; leg. H. Freitag and J. Garces; on slide; GBIFCH00592699; RUPP.