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

16. Thraulodes nigrotibialis sp. n.

( Figs 510–542 )

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. 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.

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 510–517 ). 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 ). 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 ). 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 ), 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 ). 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 ).

Hind tibia ( Figs 520–521 ): 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 ): 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 ): 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 , 533 ). 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 ). 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 ).

Male imago ( Figs 532 , 526–530 ). 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 ). Pterostigmatic cross veins dense, oblique, non-branched. Hind wing with costal projection blunt; proximal part of hind wing brown ( Fig. 536 ). Proximal coloration of fore and hind wings appears during larval development and present both in subimago and imago.

Abdominal hypodermal coloration ( Fig. 528 ): 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 ): 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 ).

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

Eggs ( Figs 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 ), 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.

Figures

FIGURES 510–521. Thraulodes nigrotibialis sp. n. 510 and 511–517, larval exuviae of two specimens at the same magnification: 510 and 511–512, parts of head with labrum and mandibles; 513, abdominal terga and sterna; 514–516, fore, middle and hind legs; 517, left half of pronotum and mesonotum; 518, young larva with brown cuticle and blackish hypodermal markings on head, thorax and abdomen; 519, anterior side of hind femur; 520, hind tibia with focus on outer-posterior row of stout setae; 521, the same with focus on outer-anterior and inner-anterior rows of stout setae (511–517, holotype).

FIGURES 522–531. Thraulodes nigrotibialis sp. n. 522, right half of subimaginal exuviae of mesonotum; 523, head and thorax of male imago in lateral view; 524–525, female imago in dorsal and lateral view; 526–527, fore and middle leg of male imago; 528, abdominal terga and sterna of male imago; 529–530, genitalia of male imago with focus on styliger and on penis; 531, genitalia of male subimago extracted from larva (522–523, 526–530, holotype).

FIGURES 532–540. Thraulodes nigrotibialis sp. n. 532, larval protogonostyli and protopenis; 533, subimaginal exuviae of genitalia; 534, genitalia of male imago in ventral view; 535, apex of penis on dorsal view; 536, hind wing; 537–540, tergalii I, III, VI and VII (532–536, holotype).

FIGURES 541–542. Thraulodes nigrotibialis sp. n., egg.

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 479–490. Thraulodes nigripes sp. n. 479–483 and 484–486, larval exuviae of two specimens at the same magnification: 479, abdominal terga; 480, left half of pronotum and mesonotum; 481 and 484–486, parts of head with labrum and mandibles; 482–483, fore and hind legs; 487, anterior side of hind femur; 488, anterior side of fore tibia; 489, hind tibia with focus on outer-posterior row of stout setae; 490, the same with focus on outer-anterior and inner-anterior rows of stout setae (484–486, holotype).

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.

FIGURES 133–142. Thraulodes panamensis sp. n. 133, pterostigma; 134–136, male imago in lateral in ventral and dorsal view; 137–138, left half of subimaginal exuviae of mesonotum of two different specimens; 139, female imago; 140–141, genitalia in lateral and ventral view; 142, costal margin of fore wing (arrows show proximal costal cross veins) (133, 134, 136, 137, 141, 142, holotype).