Labiobaetis orientis, 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 : 21-25

6. Labiobaetis orientis sp. n. Figures 12, 13, 64a

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal submarginal arc of setae composed of 14 long, feathered setae; B) labial palp segment II with a large, lobed distomedial protuberance and with segment III slightly pentagonal and slightly pointed on apex; C) hind femur slender, length ca. 4 × maximum width, dorsal margin with a row of ca. 18 curved, spine-like setae and a few stout, pointed setae near margin; D) femur and tibia of hind leg ventrally with stout, bipectinate, pointed setae; E) hind tarsal claw with 14 denticles.

Description.

Larva (Figs 12, 13).

Colouration. Unknown.

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. 12a). Rectangular, length 0.7 × maximum width. Distal margin with medial emargination and a small process. Dorsally with many medium to long, fine, simple setae; submarginal arc of setae composed of 14 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 five short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 12b, c). Incisors fused. Outer and inner sets of denticles with 4 + 4 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. 12d, e). Incisors fused. Outer and inner sets of denticles with 4 + 4 denticles. Prostheca robust, apically with small denticles and comb-shape structure. Margin between prostheca and mola straight, with few minute setae. Subtriangular process long and slender, above level of area between pros theca 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. 12f). Lingua about as long as superlingua. Lingua longer than broad; medial tuft of stout setae present; distal half laterally expanded. Superlingua rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 12g). 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 spine-like seta and six long, simple setae. Maxillary palp unknown.

Labium (Fig. 12h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with seven spine-like setae increasing in length distally; apex with two long and one medium, robust, pectinate setae; outer margin with eight long, spine-like setae; 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 three medium, simple setae; ventrally with three 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 and medium, fine, simple setae ventrally and with micropores dorsally. Segment II with a large, lobed distomedial protuberance; distomedial protuberance 0.8 × width of base of segment III; inner and outer margin both with short, fine, simple setae; dorsally with two long, spine-like, simple setae. Segment III slightly pentagonal; apex slightly pointed; length 1.1 × width; ventrally covered with medium spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Hind leg (Fig. 13a, b, c, d). Ratio of hind leg segments 1.3:1.0:0.5:0.2. Hind femur. Length ca. 4 × maximum width. Dorsal margin with a row of ca. 18 curved, spine-like setae and with a few stout, pointed setae near margin; length of setae 0.16 × maximum width of femur. Apex rounded; with some curved spine-like setae and many short, stout setae. Many stout, lanceolate, bipectinate setae and a few fine, simple setae along ventral margin; femoral patch poorly developed. Tibia. Dorsal margin with a few curved, spine-like setae. Ventral margin with a row of curved, spine-like setae and some longer, spine-like, bipectinate setae and a tuft of long, fine, simple setae on apex. Anterior surface scattered with stout, lanceolate, bipectinate setae (pectination difficult to see). Tibio-patellar suture present on basal 1/3 area. Tarsus. Dorsal margin bare. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of 14 denticles; tapering distally; with five stripes; subapical setae absent.

Tergum (Fig. 13e). Surface with irregular rows of U-shaped scale bases and scattered micropores. Posterior margin of tergum IV with triangular spines, wider than long.

Gills (Fig. 13f). Present on segments II–VII. Margin with small denticles and long, fine, simple setae. Tracheae extending from main trunk to inner and outer margins. Gill IV unknown, gill V as long as length of segments VI and 1/2 VII combined. Gill VII as long as length of segments VIII and 1/2 IX combined.

Paraproct (Fig. 13g). Distally expanded, with many 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.

Refers to the type locality, which is in the Eastern Highlands of Papua New Guinea.

Distribution.

New Guinea.

Biological aspects.

The specimen was collected at an altitude of 1700-1800 m a.s.l.

Type-material.

Holotype. Nymph (on slide, GBIFCH 00465169), Papua New Guinea, Eastern Highlands, Marawaka, Ande, 1700-1800 m, 09 Nov 2006, nr 07°01.70'S, 145°49.81'E, Balke & Kinibel (PNG 87). Deposited in ZSM.