Labiobaetis paravultuosus, 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 : 80-84

24. Labiobaetis paravultuosus sp. n. Figures 44, 45, 62c, 64b

Diagnosis.

Larva. Following combination of characters: A) labrum dorsal submarginal arc of setae composed of one plus nine long, simple setae; B) maxillary palp with segment II longer than length of segment I, segment II with excavation at inner distolateral margin; C) labial palp segment II with a hook-like distomedial protuberance; D) fore femur rather broad, length ca. 3 × maximum width, dorsal margin with a row of ca. 28 curved, spine-like setae; E) fore claw with 10 denticles; F) gills margin serrated with alternating bigger and smaller spines.

Description.

Larva (Figs 44, 45, 62c). Body length 7.8 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 light brown, femur colourless with a medial brown spot and a brown dorsal margin, tibia and tarsus 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. 44a). 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 one plus nine long, simple setae. Lateral margin with few long, spine-like setae and few long, fine, simple setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with eight short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 44b, c). Incisors fused. Outer and inner sets of denticles with 5 + 4 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. 44d, e). Incisors fused. Outer and inner sets of denticles with 4 + 3 denticles and one minute intermediate denticle. 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 slightly convex. Basal half with fine, simple setae scattered over dorsal surface.

Hypopharynx (Fig. 44f). Lingua about as long as superlingua. Lingua about as broad as long; medial tuft of stout setae present; distal half laterally expanded. Superlingua rounded; lateral margin rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 44g). 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 6-7 long, simple setae. Maxillary palp 1.2 × 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. 44h). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with 7-9 spine-like setae increasing in length distally; apex with three long, robust, pectinate setae; outer margin with six long spine-like setae increasing in length distally; 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 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 hook-like 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 2-3 long, spine-like, simple setae. Segment III slightly pentagonal; apex rounded; length 1.0 × width; ventrally covered with short and medium spine-like, simple setae and short, fine, simple setae.

Hind wing pads absent.

Foreleg (Fig. 45a, b). Ratio of foreleg segments 1.1:1.0:0.5:0.1. Femur. Length ca. 3 × maximum width. Dorsal margin with a row of ca. 28 curved, spine-like setae; length of setae 0.16 × maximum width of femur. Apex rounded; with two pairs of curved, spine-like setae and many short, stout, pointed setae. Many stout, lanceolate setae and a few fine, simple setae scattered along ventral margin; femoral patch poorly developed. Tibia. Dorsal margin with a row of curved, spine-like setae and long, fine, simple setae. Ventral margin with a row of short, 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 2/3. Tarsus. Dorsal margin with a row of short, curved, spine-like setae and long, simple setae. Ventral margin with a row of curved, spine-like setae. Tarsal claw with one row of ten denticles; tapering distally; with five stripes; subapical setae absent.

Tergum (Fig. 45c). Surface with irregular rows of U-shaped scale bases and scattered micropores. Posterior margin of tergum IV with rounded or triangular spines, about as long as wide.

Gills (Fig. 45d). 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. Gill IV as long as length of segments V and 1/2 VI combined. Gill VII as long as length of segments VIII and 1/2 IX combined.

Paraproct (Fig. 45e). Distally not 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 similarity and close relationship to L. vultuosus .

Distribution.

New Guinea.

Biological aspects.

The specimens were collected at an altitude of 1500 m a.s.l.

Type-material.

Holotype. Nymph (on slide, GBIFCH 00465213), Papua New Guinea, Enga, Wapanamanda, 1500 m, 06 Dec 2006, 05°38.11'S, 143°55.34'E, Balke & Kinibel (PNG 128). Deposited in ZSM. Paratypes. 30 nymphs (1 on slide, GBIFCH 00465214, 16 in alcohol, GBIFCH 00515223, deposited in MZL; 13 in alcohol, GBIFCH 00515224, deposited in ZSM), same data as holotype.