Labiobaetis brao, Kaltenbach & Garces & Gattolliat, 2022

Kaltenbach, Thomas, Garces, Jhoana & Gattolliat, Jean-Luc, 2022, First contribution to Labiobaetis Novikova & Kluge in Cambodia (Ephemeroptera, Baetidae), with description of two new species, ZooKeys 1123, pp. 63-81 : 63

publication ID

https://dx.doi.org/10.3897/zookeys.1123.90308

publication LSID

lsid:zoobank.org:pub:13556B2A-BE87-44F6-9A43-FCDAFE1C68CB

persistent identifier

https://treatment.plazi.org/id/A5F61492-39FC-4FBC-A77F-C5620E5EDC1E

taxon LSID

lsid:zoobank.org:act:A5F61492-39FC-4FBC-A77F-C5620E5EDC1E

treatment provided by

ZooKeys by Pensoft

scientific name

Labiobaetis brao
status

sp. nov.

Labiobaetis brao sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 6b View Figure 6

Diagnosis.

Larva. Following combination of characters: A) antennal scape with well developed distolateral process (Fig. 2g View Figure 2 ); B) dorsal surface of labrum with submarginal arc of 9-11 feathered setae (Fig. 1a View Figure 1 ); B) labial palp segment II with broad, extended, thumb-like distomedial protuberance; segment III rather oblong, apically truncate (Fig. 1h View Figure 1 ); C) fore femur rather broad, length ca 3 × maximum width, dorsal margin with 11-25 curved, short, spine-like setae (Fig. 2a View Figure 2 ); D) hind protoptera well developed; E) seven pairs of tergalii; F) paraproct distally not expanded, with ca 34 marginal spines and additional row of minute spines along inner, proximal margin (Fig. 2e, f View Figure 2 ).

Description.

Larva (Figs 1a-g, i, j View Figure 1 , 2 a-c, e-h View Figure 2 , 5a, b View Figure 5 ). Body length 6.4-8.4 mm. Cerci: ca 2/3 of body length. Paracercus: ca 2/3 of cerci length. Antenna: approximately twice as long as head length.

Colouration (Fig. 5a, b View Figure 5 ). Head, thorax and abdomen dorsally grey-brown, with pattern as in Figure 6a View Figure 6 . Abdominal tergits I and X brighter. Fore protoptera light grey-brown with dark striation. Head ventrally brownish, thorax and abdomen ventrally light grey-brown. Legs ecru to light brown, femur with grey-brown distomedial spot, apex and dorsal margin grey-brown. Caudalii grey-brown.

Antenna (Fig. 2h View Figure 2 ) with scape and pedicel subcylindrical, with well-developed distolateral process at scape.

Labrum (Fig. 1a View Figure 1 ). Subrectangular, length 0.65 × 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 9-11 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 three short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 1b, c View Figure 1 ). 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, with few minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 1d, e View Figure 1 ). 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. 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. 1f View Figure 1 ). Lingua approx. as long as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, broad; distal half laterally expanded. Superlinguae distally rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 1g View Figure 1 ). 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 spine-like seta and three long, simple setae. Maxillary palp 1.3 × as long as length of galea-lacinia; 2-segmented; palp segment II approximately as long as 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. 1i, j View Figure 1 ). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with 8-10 spine-like setae, distalmost seta much longer than other setae; apex with three medium and one short, robust setae; outer margin with ca 6 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 three medium, simple setae in anteromedial area; 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 broad, extended, 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 three long, spine-like setae near outer margin. Segment III rather oblong, apically truncate; length 1.1 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera well developed.

Foreleg (Fig. 2a, b View Figure 2 ). Ratio of foreleg segments 1.4:1.0:0.6:0.2. Femur. Length ca 3 × maximum width. Dorsal margin with 11-25 curved, short, spine-like setae, often one seta additionally near margin in basal area; length of setae 0.14 × maximum width of femur. Apex rounded, with a spine-like seta 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, and some fine, simple setae; many more stout, apically rounded setae along dorsal margin; on apex one seta of same type. Ventral margin with row of short, curved, spine-like setae, on apex some longer setae and a tuft of fine, simple setae. Anterior surface with row of stout, lanceolate setae near ventral margin. Patellatibial suture present on basal 1/3 area. Tarsus. Dorsal margin with row of short, stout setae and some fine, simple setae. Ventral margin with row of curved, spine-like setae. Claw with one row of 7-10 denticles; distally pointed; with ca four stripes; subapical setae absent.

Middle and hind legs. As foreleg, but with reduced or rudimentary femoral patch on middle femur, and reduced or well developed on hind femur.

Terga (Fig. 2c View Figure 2 ). Surface with irregular rows of U-shaped scale bases. Posterior margin of tergum IV with spines varying between mostly triangular to mostly rounded, wider than long.

Tergalii (Fig. 2e View Figure 2 ). Present on segments I-VII. Margins with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Tergalius I ca 2/3 length of segment II. Tergalius IV as long as length of segments V and 1/2 VI combined. Tergalius VII as long as length of segment VIII.

Paraproct (Fig. 2f, g View Figure 2 ). Distally not expanded, with ca 34 stout, marginal spines, and additional row of minute spines along inner, proximal margin. Surface scattered with U-shaped scale bases and fine, simple setae. Cercotractor with numerous small, marginal spines.

Etymology.

The new species is dedicated to the indigenous Brao people from northeastern Cambodia.

Distribution.

Cambodia (Fig. 6b View Figure 6 ).

Biological aspects.

The specimens were mainly collected in secondary forest remnants at altitudes of 100 m, partly on littoral gravel.

Type material.

Holotype. Cambodia • larva; Kampong Speu Province, Kokie waterfall, sec. forest remnants; 110 m; 11°12'11"N, 104°03'49"E; 12.07.2018; leg. H. Freitag and J. Garces; on slide; GBIFCH00592700; MZL. Paratypes. Cambodia • 8 larvae; same data as holotype; 1 on slide; GenBank ON982739; GBIFCH00829878; RUPP; 1 on slide; GBIFCH00975576; MZL; 6 in alcohol; GBIFCH00975580, GBIFCH00975581; MZL • 1 larva; Kampong Speu Province, Chambok River, 1.83 Km from Chambok Community, sec. forest, littoral gravel; 240 m; 11°21'58"N, 104°06'17"E; 11.07.2018; leg. H. Freitag and J. Garces; on slide; GBIFCH00592730; RUPP.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Ephemeroptera

Family

Baetidae

Genus

Labiobaetis