Thraulodes niger, 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 : 98-100

13. Thraulodes niger sp. n.

( Figs 411–449 )

Etymology. Allusion to dark brown, nearly black color of male imago.

Material examined. Holotype: L-S-I ♂ {specimen [XLIV] (4) 2013}, PERU, Region Junin, Provincia Satipo, Puerto Prado (11°09’S, 74°14’W), 17.IX.2013, coll. N. Kluge & L. Sheyko. Paratypes: the same locality and collectors, 12–17.IX.2013: 2 L-S/I ♂, 4 L-S ♂, 1 larva; Pichanaki, Rio Sotorani (10°57’S, 74°52’W), 8.I.2006, coll. N. Kluge: 1 L-S ♂, 2 larvae; Region Huanuco, Tingo Maria, Rio Cantaria , Puente Perez (9°21’S, 75°58’W), 22.I.2006, coll. N. Kluge: 1 L-S/I ♀.

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 412–420 ). Head with clypeus brown, frons lighter. Pronotum brown, bordered by light laterally, often with other blanks of characteristic form ( Figs 415, 420 ). Each abdominal tergum with characteristic coloration: area adjacent to anterior margin together with antero-median and sublateral areas brown, remainder part contrastingly light, nearly colorless; size of brown and light areas varying individually. Femora with brown areas and blanks; tibiae and tarsi uniformly brownish.

HYPODERMAL COLORATION. Abdominal terga, besides peculiar cuticular coloration (see above) with blackish transverse stripes bordering posterior margins of terga and with paired longitudinal-triangular spots corresponding to grayish-brown spots of imago ( Fig. 421 ). Tergalii colorless, tracheae black ( Fig. 421 ).

SHAPE AND SETATION. Clypeus parallel-sided or widened distally; labrum 1.15–1.3 times wider than clypeus ( Fig. 413 ). Labrum widest at midlength; initial fore margin (turned ventrally) without median emargination, shallowly concave, with all 5 denticles wide; anterior transverse setal row regular (as in Fig. 88 ), as wide as all 5 denticles. Maxilla with 19–21 pectinate setae in apical-ventral row.

Femora: Stout setae on anterior surface parallel-sided or narrowed distally, blunt ( Fig. 422 ). Irregular row of hairs near inner margin absent on fore and middle femora, sparse on hind femur.

Fore tibia ( Figs 423–424 ): outer hairs form two irregular rows; inner-anterior row of recurved hairs absent; inner-anterior row of stout setae absent or represented by one 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 3–4 setae in cross section).

Hind tibia ( Figs 425–426 ): each of three rows of stout setae—outer-anterior, outer-posterior and inner-anterior ones—contains moderately long, narrowing distally and blunt stout setae; outer-anterior row, besides this, can contain long spoon-like setae; hairs located between outer-anterior and outer-posterior rows, form one irregular row (besides row of hairs posteriad of outer-posterior row of stout setae).

Claws with 3–5 denticles on rigid portion, with one several rows of minute denticles on articulatory portion ( Fig. 411 ).

Tergalii ( Figs 444–447 ): wide; on both lamellae main trachea with branches directed toward costal and anal margins; dorsal lamella bent backward, with costal margin more convex than anal, widest in proximal or middle part, gradually narrowed toward apex, with slender apical filament; ventral lamella widest near base, gradually narrowed toward apex, with slender apical filament.

Male genitalia in last larval instar ( Fig. 442 ): protogonostyli moderately long and separated one from another by deep emargination. Each protopenis lobe with smoothly projected gonopore-bearing process located near median margin; gonopores opened caudally.

Subimago ( Figs430, 431 , 441 ).CUTICULAR COLORATION.Cuticle mostly brown.Mesonotum darker brown, with darker brown antelateroparapsidal and lateroparapsidal sutures, lighter oblique stripes on posterior scutal protuberances and colorless achromozones; medioscutal and submedioscutal chromozones equally colored by brown, separated by darker brown medioscutal suture ( Fig. 431 ). On all legs femur light brown, bordered by darker brown on outer and inner margins and apically; tibia and tarsus light brown. Wings dark brown due to dark brown ring at base of each microtrichion; microtrichia blackish-brown ( Fig. 438 ). Abdominal terga, sterna, gonostyli and caudalii light 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 all legs (as in Fig. 473 ).

Male imago ( Figs 427–429 ). Coloration of body and legs nearly uniformly dark brown. Head and antennae dark brown. Dorsal eyes contiguous medially, dull orange. Thorax dorsally, laterally and ventrally equally dark brown, with pleural membranes brownish ocher.

Cuticle of legs light brown; hypodermal pigmentation of femur, tibia and tarsus of all legs uniformly dark brown.

Fore and hind wing with longitudinal and cross veins ocher or brown. Costal and subcostal fields of fore wing colored with yellowish-brown. Costal field proximad of bulla with delicate cross veins. Pterostigmatic cross veins dense, oblique, arched, partly branched an anastomosed. Hind wing with brown macula on costal brace ( Fig. 443 ).

Abdominal hypodermal coloration: All terga and sterna brown; terga with posterior margin darker brown; each tergum II–VII with of pair darker grayish-brown longitudinal triangular maculae diminishing from anterior to pos- terior terga. Caudalii brown, with joinings darkened.

Genitalia ( Figs 432–433 , 439–441 ): Styliger, gonostyli and penis uniformly brown. Dorsal extension of styliger prominent. Penis lobes long, narrow and slightly divergent; each penis lobe parallel-sided, without lateral pouch, not widened apically, without ear. Telopenes in form of spear-like rolls, attached at apices of penis lobes, directed caudally-medially, stout, with groove opened dorsally-laterally ( Fig. 439 ).

Female imago ( Figs 434–437 ). Coloration of head, thorax, wings and caudalii as in male. Tibia of middle and hind legs in proximal half brown, in distal half ocher (one specimen examined); in other respects coloration of legs as in male.

Eggs ( Figs 448–449 ). Mostly barrel-shaped. Each KTC surrounded by ring-like cover with radial folds. Other chorion with shallow folds, nearly without protuberances.

Dimension. Fore wing length (and approximate body length) 8–9.5 mm.

Comparison. The male imago of Thraulodes niger sp. n. has a penis structure similar to that of Th. ephippiatus Traver & Edmunds 1967 , Th. cochunaensis Domínguez 1987 and Th. basimaculatus Giordano & Domínguez 2005 , differing from these three species, as well as from other formerly known species of Thraulodes , by uniformly dark brown femora and tibiae of all legs. Th. niger sp. n. differs from Th. nigrabdominalis sp. n. by colored costal and subcostal fields of fore wing and by the presence of paired dark maculae on abdominal terga.

The larva of Th. niger sp. n. clearly differs from all other known species of Thraulodes by a peculiar and constant cuticular coloration of abdominal terga ( Figs 414, 419, 421 ). Both larva and winged stages of Th. niger sp. n. can be distinguished from related species by paired longitudinal hypodermal maculae on abdominal terga ( Figs 421 , 429, 430 ).

Figures

FIGURES 411–426. Thraulodes niger sp. n. 411, larval claw; 412–413, 414–418 and 419–420, larval exuviae of three specimens at the same magnification; 421, larval abdomen with ocher cuticular markings and blackish hypodermal markings; 422, anterior side of hind femur; 423, anterior side of fore tibia; 424, the same with focus on more posterior setae; 425, hind tibia with focus on outer-posterior row of stout setae; 426, the same with focus on outer-anterior and inner-anterior rows of stout setae (412–413, holotype).

FIGURES 427–438. Thraulodes niger sp. n. 427–428, head and thorax of male imago in lateral and dorsal view; 429, abdominal terga and sterna of male imago; 430, the same of male subimago; 431, subimaginal mesonotum; 432–433, genitalia of male imago with focus on styliger and on penis; 434, female imago; 435, its left fore wing; 436–437, its fore and middle legs; 438, subimaginal exuviae of fore wing (427–429, 432–433, 438, holotype).

FIGURES 439–447. Thraulodes niger sp. n. 439, apex of penis in dorsal view; 440, genitalia of male imago in ventral view; 441, their subimaginal exuviae; 442, larval protogonostyli and protopenis; 443, hind wing; 444–447, tergalii I, III, VI and VII.

FIGURES 448–449. Thraulodes niger sp. n., eggs.

FIGURES 86–93. Thraulodes telegraphicus. 86, median longitudinal section of labrum in usual condition; 87, the same, in spread condition; 88, labrum in spread condition in dorsal view (setal rows shown as dotted lines); 89, transverse section of hind tibia; 90–93, tergalii I, III, VI and VII. Abbreviations: anter.r, anterior transverse row of setae; dent., five denticles separated by six sensilla; poster.r, posterior transverse row of setae; i.f, inner field of stout pointed setae; i-a.h, inner-anterior recurved hairs; i-a.r, inner-anterior row of stout setae; o-a.r, outer-anterior row of stout setae; o.h, outer hairs; o-p.r, outer-posterior row of stout setae; p.r, row of posterior pointed pectinate setae.

FIGURES 464–473. Thraulodes nigrabdominalis sp. n. (holotype). 464, left half of subimaginal exuviae of mesonotum; 465, 466, male imago; 467–469, fore, middle and hind legs of male imago; 470, subimaginal exuviae of fore leg; 471, genitalia of male imago; 472, apex of penis; 473, subimaginal exuviae of tarsus.