Labiobaetis magnovaldus, 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 : 43-48

13. Labiobaetis magnovaldus sp. n. Figures 24, 25, 60b, 65a

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal submarginal arc of setae composed of one plus six or seven long, simple setae; B) maxillary palp about as long as galea-lacinia, excavation on inner distal margin of segment II poorly developed; C) labial palp segment II with a compact, rounded distomedial protuberance; D) fore femur rather broad, length ca. 3 × maximum width, dorsal margin with a row of ca. 34 curved, spine-like setae and many stout, pointed setae near margin; E) fore claw with one row of 11-12 denticles; F) tracheae of gills restricted to main trunk, without pigmentation; G) paraproct surface with slightly lanceolate setae and fine, simple setae.

Description.

Larva (Figs 24, 25, 60b). Body length 6.8 mm; antenna approximately twice as long as head length.

Colouration. Head, thorax and abdomen dorsally brown, head and thorax with bright median, dorsal suture, forewing pads with bright striation. Head, thorax and abdomen ventrally brown, legs light brown, dorsal magin of femur and tibia brown, caudal filaments brown.

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

Labrum (Fig. 24a). Rectangular, length 0.6 × maximum width. Distal margin with medial emargination and a small process. Dorsally with medium, fine, simple setae and a few slightly lanceolate setae; submarginal arc of setae composed of one plus 6-8 long, simple setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, pectinate setae and medial long, bifid, pectinate setae; ventral surface with seven short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 24b, c). Incisors fused. Outer and inner sets of denticles with 4 + 3 denticles. Inner margin of innermost denticle with a row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola slightly convex, with minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 24d, e). Incisors fused. Outer and inner sets of denticles with 3 + 3 denticles. Prostheca robust, apically denticulate. 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 (Fig. 24f). Lingua longer than superlingua. Lingua about as broad as long; medial tuft of stout setae present; distal half not expanded. Superlingua rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 24g). Galea-lacinia with three 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 about as long as length of galea-lacinia; two segmented. Palp segment II 1.9 × length of segment I. Setae on maxillary palp fine and simple, scattered over surface of segments I and II. Apex of last segment rounded, with slight excavation at inner distolateral margin.

Labium (Fig. 24h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with 11-12 spine-like setae increasing in length distally; apex with three long, robust, pectinate setae and one short, robust seta; outer margin with seven spine-like setae increasing in length distally; ventral surface with short, fine, simple setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, apically pectinate setae; dorsally with 2-3 medium, simple setae; ventrally with five 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 short, fine, simple setae ventrally and micropores dorsally. Segment II with a compact, rounded distomedial protuberance; distomedial protuberance 0.5 × width of base of segment III; inner and outer margin both with short, fine, simple setae; dorsally with row of five long, spine-like, simple setae. Segment III conical; apex rounded; length 1.0 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg (Fig. 25a, b). Ratio of foreleg segments 1.3:1.0:0.7:0.3. Femur. Length ca. 3 × maximum width. Dorsal margin with row of ca. 34 curved, spine-like setae and with many stout, pointed setae near margin; length of setae 0.15 × maximum width of femur. Apex rounded; with one curved, spine-like seta and many short, stout, pointed 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. Ventral margin with a row of curved, spine-like setae, apically longer and dense and with a tuft of long, fine, simple setae. Anterior surface scattered with many stout, lanceolate setae. Tibio-patellar suture present on basal 1/2. Tarsus. Dorsal margin with a row of short, spine-like setae and long, simple setae. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of 11-14 denticles; tapering distally; with 5-7 stripes; subapical setae absent.

Tergum (Fig. 25c). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae, scales egg-shaped. Posterior margin of tergum IV with rounded spines, about as long as wide.

Gills (Fig. 25d). Present on segments II–VII. Margin with small denticles intercalating long, fine, simple setae. Tracheae restricted to main trunk. Gill IV as long as length of segments V and 1/2 VI combined. Gill VII as long as length of segment VIII.

Paraproct (Fig. 25e). Distally slightly expanded, with many marginal, stout spines. Surface with U-shaped scale bases and scattered fine, slightly lanceolate setae as well as fine, simple setae. Postero-lateral extension (cercotractor) with small marginal spines.

Terminal filament 0.6 × length of cerci.

Etymology.

Latin for "very high", refers to the high altitude (2900 m a.s.l.) of the type locality.

Distribution.

New Guinea.

Biological aspects.

The specimens were collected in altitudes of 2200 m a.s.l. and 2900 m a.s.l. (in forest).

Type-material.

Holotype. 1 Nymph (on slide, GBIFCH 00465187), Papua New Guinea, Simbu Prov., 05°49'S, 145°04.5'E, Mt. Wilhelm, Pindaunde Creek, 2900 m a.s.l. (in forest), S3 (oria.4), 18 Aug 1999, leg. L. Čížek. Deposited in MZL. Paratypes. 8 nymphs (2 on slides, GBIFCH 00465188, GBIFCH 00465189, 6 in alcohol, GBIFCH 00515266, GBIFCH 00508122, deposited in MZL), same data as holotype; 7 nymphs (1 on slide, GBIFCH 00465190, 3 in alcohol, GBIFCH 00515267, deposited in MZL; 3 in alcohol, GBIFCH 00515268, deposited in ZSM), 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).