Labiobaetis inopinatus, 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 : 96-98

28. Labiobaetis inopinatus sp. n. Figures 52, 53, 64b

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal submarginal arc of setae composed of 21 long, lanceolate, apically pectinate setae; B) maxillary palp much longer than length of galea-lacinia, apically rounded, with excavation at inner distolateral margin; C) labial palp segment II with a large, lobed distomedial protuberance, segment III slightly pentagonal, apically slightly pointed; D) fore femur very slender, length ca. 5 × maximum width, dorsal margin with a row of ca. 12 curved, spine-like setae; E) fore claw with one row of eleven denticles.

Description.

Larva (Figs 52, 53).

Colouration. Unknown.

Labrum (Fig. 52a, b). Rectangular, length 0.7 × 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 21 long, lanceolate, apically pectinate setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid setae; ventral surface with seven short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 52c, d). Incisors fused. Outer and inner sets of denticles with 4 + 3 denticles plus one small intermediate denticle. Inner margin of innermost denticle with a row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola straight, with minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 52e, f). 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 minute denticles towards 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. 52g). Lingua shorter than superlingua. Lingua longer than broad; medial tuft of stout setae present; distal half laterally expanded. Superlingua slightly concave; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 52h). 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 1.7 × as long as length of galea-lacinia; two segmented. Palp segment II 1.2 × 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 excavation at inner distolateral margin.

Labium (Fig. 52i, j). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with eight spine-like setae increasing in length distally; apex with three long, robust, pectinate setae; outer margin with five long, spine-like setae; ventral surface with short, fine, simple, scattered setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, apically pectinate setae; dorsally with five 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, fine, simple setae ventrally and micropores dorsally. Segment II with a large, lobed distomedial protuberance; distomedial protuberance 0.7 × 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 1.2 × width; ventrally covered with short and medium spine-like, simple setae and short, fine, simple setae.

Hind wing pads unknown.

Foreleg (Fig. 53a, b). Ratio of foreleg segments 1.1:1.0:0.5:0.1. Femur. Length ca. 5 × maximum width. Dorsal margin with a row of ca. 12 curved, spine-like setae; length of setae 0.2 × maximum width of femur. Apex rounded; with one pair of curved, spine-like setae and some short, stout, pointed setae. Many stout, lanceolate setae along ventral margin; femoral patch absent. Tibia. Dorsal margin with a row of stout, lanceolate setae and very fine, simple 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 setae. Tibio-patellar suture present on basal 1/3. Tarsus. Dorsal margin bare. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of eleven denticles; tapering distally; with three stripes; subapical setae absent.

Tergum . Unknown.

Gills . Unknown.

Paraproct . Unknown.

Etymology.

Latin word for unexpected, refers to the unexpected finding of this species amongst other material.

Distribution.

New Guinea.

Type-material.

Holotype. Nymph (on slide, GBIFCH 00465230), Papua New Guinea, Gulf Prov., Supa-Hala, 1032 m, 10 Nov 2002, forest stream, K. Sagata leg. Deposited in ZSM.