Labiobaetis gladius, Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2018

Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2018, The incredible diversity of Labiobaetis Novikova & Kluge in New Guinea revealed by integrative taxonomy (Ephemeroptera, Baetidae), ZooKeys 804, pp. 1-136 : 30-34

9. Labiobaetis gladius sp. n. Figures 17, 18, 59c, 64b

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal arc of setae composed of one plus 9-11 long, simple setae; B) both mandibles with outermost denticles blade-like; C) hypopharynx with concave distal margin of superlingua; D) maxillary palp somewhat longer than length of galea-lacinia; E) fore femur broad, length 2.5 × maximum width, dorsal margin with a row of ca. 37 curved, spine-like setae and distally with some stout, pointed setae near margin; F) gills margin serrate with alternating smaller and bigger denticles intercalating long, fine, simple setae; G) spines at posterior margin of tergum IV rounded, wider than long; H) paraproct distally not expanded.

Description.

Larva (Figs 17, 18, 59c). Body length 6.7 mm; cerci: 3.7 mm; terminal filament: 2.8 mm.

Colouration. Head, thorax and abdomen dorsally brown, head and thorax with bright median, dorsal suture, forewing pads with slightly darker striation. Head, thorax and abdomen ventrally light brown, legs light brown and with brown marks as in Fig. 59c, caudal filaments light brown.

Antenna with scape and pedicel sub-cylindrical, without distolateral process at scape; flagellum with broad, apically blunt spines and fine, simple setae on apex of each segment.

Labrum (Fig. 17a). Rectangular, length 0.7 × maximum width. Distal margin with medial emargination and a small process. Dorsally with short to medium, fine simple setae and some short, robust, simple setae on posterior area; submarginal arc of setae composed of one plus 9-11 long, simple setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, pectinate setae, centrally bifid; ventral surface with seven short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 17b, c). Incisors fused. Outer and inner sets of denticles with 3 + 4 denticles, outermost denticle blade-like. Inner margin of innermost denticle with a row of thin setae. Prostheca robust, apically with small denticles and comb-shape structure. Margin between prostheca and mola straight. Tuft of setae at apex of mola present.

Left mandible (Fig. 17d, e). Incisors fused. Outer and inner sets of denticles with 3 + 4 denticles plus one minute intermediate denticle, outermost denticle blade-like. Prostheca robust, apically with small denticles and comb-shape structure. Margin between prostheca and mola straight. 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 (Fig. 17f). Lingua longer than superlingua. Lingua longer than width; medial tuft of stout setae present; distal half laterally expanded. Superlingua concave; lateral margin straight; fine, long, simple setae along distal margin.

Maxilla (Fig. 17g). Galea-lacinia with two simple, robust apical setae under crown. 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 eight long, simple setae. Maxillary palp slightly longer than length of galea-lacinia; two segmented. Palp segment II 1.3 × length of segment I. Setae on maxillary palp fine and simple, scattered over surface of segments I and II. Apex of last segment slightly pointed, without excavation at inner distolateral margin.

Labium (Fig. 17h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with nine spine-like setae increasing in length distally; apex with three long, robust setae; outer margin with six long spine-like setae increasing in length distally; ventral surface with few short, fine, simple setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, apically pectinate setae; dorsally with row of four medium, simple setae; ventrally with four long, spine-like setae near inner margin. Labial palp with segment I 0.7 × length of segments II and III combined. Segment I covered with micropores dorsally and ventrally with fine, simple setae along margins. Segment II with a short, thumb-like distomedial protuberance; distomedial protuberance 0.4 × width of base of segment III; inner and outer margin both with fine, simple setae; dorsally with row of 5-6 spine-like, simple setae, decreasing in length distally. Segment III oblong; apex slightly pointed; length 1.3 × width; ventrally covered with long and medium spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg (Fig. 18a, b). Ratio of foreleg segments 1.6:1.0:0.7:0.3. Femur. Length 2.5 × maximum width. Dorsal margin with a row of ca. 37 curved, spine-like setae and distally with some stout, pointed setae near margin; length of setae 0.18 × maximum width of femur. Apex rounded; with one pair of curved, spine-like setae and many short, stout, apically rounded setae. Many stout, lanceolate setae and a few fine, simple setae along ventral margin; femoral patch poorly developed. Tibia. Dorsal margin with a row of short, curved, spine-like setae and long, fine, simple setae, apically with two longer, curved, spine-like setae. Ventral margin with a row of short, spine-like setae and one stout, spine-like seta and a tuft of long, fine, simple setae on apex. Anterior surface scattered with many stout, lanceolate setae and fine, simple setae. Tibio-patellar suture present on basal 3/4. Tarsus. Dorsal margin with a row of short, spine-like setae and some long, fine, simple setae. Ventral margin with a row of curved, spine-like setae on margin. Tarsal claw with one row of eleven denticles; tapering distally; with six stripes; subapical setae absent.

Tergum (Fig. 18c). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae and micropores, scales oblong. Posterior margin of tergum IV with rounded spines, wider than long.

Gills (Fig. 18d). Present on segments II–VII. Margin with alternating smaller and bigger denticles intercalating long, fine, simple setae. Tracheae extending from main trunk to inner and outer margins, pigmentation limited to main trunk and extensions to inner margin. Gill IV as long as length of segments V and 1/2 VI combined. Gill VII as long as length of segments VIII and 1/3 IX combined.

Paraproct (Fig. 18e). Distally not expanded, with ca. 22 marginal, stout spines. Surface with U-shaped scale bases and scattered fine, simple setae and micropores. Postero-lateral extension (cercotractor) with small marginal spines.

Etymology.

Latin word for sword, refers to the blade-like outermost denticle of the mandibles.

Distribution.

New Guinea.

Biological aspects.

The specimens were collected at altitudes of 1800-3210 m a.s.l.

Type-material.

Holotype. Nymph (on slide, GBIFCH 00465172), Papua New Guinea, Simbu Prov., 05°49.96'S, 145°06.129'E, (GPS), Mt. Wilhelm, Pindaunde Creek, 2350 m a.s.l. (7915 ft), S5 (oria.6), 18 Aug 1999, leg. L. Čížek. Deposited in MZL. Paratypes. 7 nymphs (3 on slides, GBIFCH 00465173, GBIFCH 00465177, GBIFCH 00465178, 4 in alcohol, GBIFCH 00515241, deposited in MZL), same data as holotype; 44 nymphs (2 on slides, GBIFCH 00465174, GBIFCH 00465175, 27 in alcohol, GBIFCH 00515242, GBIFCH 00508132, deposited in MZL; 15 in alcohol, GBIFCH 00515243, deposited in ZSM), Papua New Guinea, Simbu Prov., 05°48.050'S, 145°04.150'E, (GPS), Mt. Wilhelm, Pindaunde Creek, 3210 m a.s.l., (10895 ft), S2 (oria.3), 17 Aug 1999, L. Čížek leg; 52 nymphs (1 on slide, GBIFCH 00465176, 32 in alcohol, GBIFCH 00515239, GBIFCH 00508124, GBIFCH 00508133, deposited in MZL; 20 in alcohol, GBIFCH 00515240, deposited in ZSM), Papua New Guinea, Simbu Prov., 05°49.033'S, 145°5.271'E, (GPS), Mt. Wilhelm, Pindaunde Creek, 2600 m a.s.l. (near fish farm), (9181 ft GPS), S4 (oria.5), 18 Aug 1999, L. Čížek leg.

Additional material.

5 nymphs (1 on slide, GBIFCH 00465179, 4 in alcohol, GBIFCH 00515275, GBIFCH 00508135, deposited in MZL), Papua New Guinea, Western Highlands, Simbai, 1800-2000 m, 26 Feb 2007, 05°15.87'S, 144°32.72'E, Kinibel (PNG 134); 2 nymphs (1 on slide, GBIFCH 00465180, 1 in alcohol, GBIFCH 00515261, deposited in MZL), Papua New Guinea, Eastern Highlands, Akameku-Brahmin, Bismarck Range, 2200 m, 23 Nov 2006, 05°56.80'S, 145°22.24'E, Balke & Kinibel (PNG 106).