Thraulodes nigrotibialis, Kluge, Nikita J., 2020

Kluge, Nikita J., 2020, Systematic position of Thraulodes Ulmer 1920 (Ephemeroptera: Leptophlebiidae) and descriptions of new and little-known species, Zootaxa 4756 (1), pp. 1-142 : 114-119

publication ID 10.11646/zootaxa.4756.1.1

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Thraulodes nigrotibialis

sp. n.

16. Thraulodes nigrotibialis sp. n.

( Figs 510–542 View FIGURES 510–521 View FIGURES 522–531 View FIGURES 532–540 View FIGURES 541–542 )

Etymology. Allusion to uniformly dark brown, nearly black color of all tibiae of imago.

Material examined. Holotype: L-S-I ♂ (specimen [V] (1) 2013}, PERU, Region Loreto, Provincia Ucayali, Aguas Termales , 17 km NNE Contamana (7°12’S, 74°57’W), 31.VII.2013, coll. N. Kluge & L. Sheyko. GoogleMaps Paratypes: the same locality and collectors, 29.VII–2.VIII.2013: 2 L-S-I ♀, 1 L-S ♀, 1 L/S ♂, 1 L/S ♀, 33 larvae. GoogleMaps


Larva. CUTICULAR COLORATION ( Figs 510–517 View FIGURES 510–521 ). Dorsal side of head, thorax and abdomen mostly brown with few blanks: pronotum bordered by light laterally; abdominal terga with blanks on lateral parts, area mediad of tergalii attachments nearly unicolor brown. Femora mostly brown, with blanks; tibiae and tarsi uniformly brown.

HYPODERMAL COLORATION ( Fig. 518 View FIGURES 510–521 ). Pronotum with paired blackish stripes running parallel to lateral margins. Abdominal terga, besides uniform cuticular coloration (see above) with blackish transverse stripes bordering posterior margins of some terga and with paired transverse-triangular spots corresponding to gray-brown markings of imago. Tergalii colorless, tracheae black).

SHAPE AND SETATION. Clypeus parallel-sided or widened distally; labrum 1.3–1.35 times wider than clypeus ( Fig. 510 View FIGURES 510–521 ). Labrum widest at 0.4 length from base; initial fore margin (turned ventrally) without median emargination, with all 5 denticles wide; anterior transverse setal row regular (as in Fig. 88 View FIGURES 86–93 ), as wide as all 5 denticles. Maxilla with 14–15 pectinate setae in apical-ventral row.

Femora: Stout setae on anterior surface parallel-sided or narrowed distally, apically blunt ( Fig. 519 View FIGURES 510–521 ). Irregular row of hairs near inner margin absent on fore femur, present on middle and hind femora.

Fore tibia: outer hairs form two irregular rows; inner-anterior row of recurved hairs absent; inner-anterior row of stout setae represented by few (1–3) blunt stout setae near tibia base; inner field of stout pointed setae dense (i.e. setae longer than distances between them), consists of pointed bipectinate and smooth setae, situated irregularly (about 2–3 setae in cross section) (as in Th. nigripes— Fig. 488 View FIGURES 479–490 ).

Hind tibia ( Figs 520–521 View FIGURES 510–521 ): both outer-anterior and outer-posterior rows of stout setae consist numerous shorter blunt stout setae and fewer long spoon-like stout setae; hairs located between these rows, numerous and form more than one row (besides row of hairs posteriad of outer-posterior row of stout setae); stout setae of inner-anterior row moderately long, parallel-sided and truncated.

Claws with 5–6 denticles on rigid portion, with or without minute denticles on articulatory portion.

Tergalii ( Figs 537–540 View FIGURES 532–540 ): moderately wide; on both lamellae main trachea with branches directed toward costal and anal margins; dorsal lamella with costal margin most convex in proximal part and anal margin most convex in distal part, gradually narrowed toward apex, with slender apical filament; ventral lamella widest near base, gradually narrowed toward apex, with slender apical filament. In holotype, both lamellae of each tergalius (i.e. all 28 lamellae) anomalous, oval or ellipsoid, apically blunt, without apical filament, variable in size and proportions; the same in 2 other larvae.

Male genitalia in last larval instar ( Fig. 532 View FIGURES 532–540 ): protogonostyli moderately long and separated one from another by deep emargination. Each protopenis lobe with gonopore-bearing process sharply projected and bent laterally; gonopores opened caudally-laterally.

Subimago ( Figs 522 View FIGURES 522–531 , 533 View FIGURES 532–540 ). CUTICULAR COLORATION. Cuticle mostly light brown. Mesonotum darker brown, with darker brown antelateroparapsidal and lateroparapsidal sutures, lighter oblique stripes on posterior scutal protuberances and colorless achromozones; medioscutal chromozone somewhat darker than submedioscutal chromozone ( Fig. 522 View FIGURES 522–531 ). On all legs femur light brown, bordered by darker brown on outer and inner margins and apically; tibia and tarsus brown. Cuticle of wings colorless, microtrichia brown. Abdominal terga light brown, diffusively darkened medially; sterna colorless; gonostyli brown.

TEXTURE. On tarsi of all legs, 1st tarsomere with microtrichia (as tibia), 2nd–5th tarsomeres coved by blunt microlepides; pointed microlepides present near apical margins of 2nd–4th tarsomeres of middle and hind legs (as in Fig. 473 View FIGURES 464–473 ).

Male imago ( Figs 532 View FIGURES 532–540 , 526–530 View FIGURES 522–531 ). Head dark brown with dark ocher macula at middle. Antennae dark brown. Dorsal eyes contiguous medially, grayish. Pronotum dark brown with dark ocher (as in female—Fig. 534); propleura ocher with blackish-brown oblique dorso-ventral stripe; prosternum brown. Meso and metathorax dorsally, laterally and ventrally equally dark brown, with pleural membranes brownish ocher.

Legs of all pairs with brown cuticle and following hypodermal coloration on ocher background: Femur with diffusive blackish-brown band occupying proximal 1/4 and multicolored apical band occupying distal 1/2 of femur; multicolored band mostly orange, proximally diffusively bordered by blackish-brown, on inner and outer sides with blackish-brown longitudinal stripes, apically blackish-brown. Tibia and tarsus entirely blackish-brown. In holotype, relation of fore femur to fore wing length 70:305; proportions femur/tibia/tarsomeres on fore leg 70:90:3:18:16:12:9; on middle leg 63:67:2:4:3:2:7; on hind leg 78:75:2:4:3:2:7.

Fore wing with dark brown band just distad of costal brace; longitudinal and cross veins ocher-brownish. Costal cross veins proximad of bulla few, colorless and very thin, so that visible only under high magnification (as in Fig. 142 View FIGURES 133–142 ). Pterostigmatic cross veins dense, oblique, non-branched. Hind wing with costal projection blunt; proximal part of hind wing brown ( Fig. 536 View FIGURES 532–540 ). Proximal coloration of fore and hind wings appears during larval development and present both in subimago and imago.

Abdominal hypodermal coloration ( Fig. 528 View FIGURES 522–531 ): Tergum I mostly gray-brown. Terga II–V translucent, medi- ally light brownish, laterally whitish, each with pair of gray-brown lateral markings. Tergum VI whitish with red- dish-brown, with smaller gray-brown lateral markings. Terga VII–X mostly reddish-brown, laterally whitish; each tergum VII–IX with pair of lateral longitudinal brown stripes. Terga IV–IX with posterior margin bordered by gray-brown. Lateral tracheae partly colored with gray, with blackish stigmatic spots. Abdominal sterna whitish with grayish nerve ganglia, sterna VII–VIII with diffusive brown hypodermal markings; sternum IX laterally with cuticle brownish. Caudalii in proximal part dark brown, in middle part with alternated 3 dark brown and 1 colorless segment, in distal part with alternated dark brown and colorless segments.

Genitalia ( Figs 529–535 View FIGURES 522–531 View FIGURES 532–540 ): Styliger and gonostyli with cuticle light brown; 2nd segment of gonostylus with dark brown hypodermal coloration. Dorsal margin of styliger slightly convex, without median extension. Penis lobes gradually widened toward apex, without lateral pouches, apically with well-expressed ears directed caudally. Medio-ventral ridge greatly projected and apically integrated with oblique preapical ridge to form integral lapel with rounded margin. Telopenes in form of spear-like rolls, attached on dorsal side, directed caudally-medially-ventrally, stout, with groove opened dorsally-laterally ( Fig. 535 View FIGURES 532–540 ).

Female imago ( Figs 524–525 View FIGURES 522–531 ). Coloration of head, thorax, legs, wings and caudalii as in male.Abdominal terga brown with ocher.

Eggs ( Figs 541–542 View FIGURES 541–542 ). Mostly barrel-shaped. Each KTC surrounded by ring-like cover with radial folds. Other chorion rugose, nearly without protuberances.

Dimension. Fore wing length (and approximate body length) 7.5–9 mm.

Comparison. Besides Th. nigrotibialis sp. n., the tibiae of all legs in imaginal and subimaginal stages are uniformly dark brown only in Th. niger sp. n., Th. nigrabdominalis sp. n. and Th. nigripes sp. n. The new species Th. nigrotibialis differs from all of them by coloration of the femora of all legs, which are not uniformly brown, but twice-banded ( Figs 526–527 View FIGURES 522–531 ), as in many other Thraulodes . Genitalia of Th. nigrotibialis sp. n. differ from that of Th. niger sp. n., Th. nigrabdominalis sp. n. and Th. nigripes sp. n. by absence of median extension of styliger. The penis of Th. nigrotibialis sp. n. is clearly different from that of Th. niger sp. n. and Th. nigrabdominalis sp. n., while penis structure of Th. nigripes sp. n. is unknown.