Thraulodes nigripes, 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 : 107-114

15. Thraulodes nigripes sp. n.

( Figs 479–509 )

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

Material examined. Holotype: L/S ♂ {slide 14.V.2006 -1}, PERU, Reg. Huanuco, Aquaytia, Pampa Yurac (9°04’S, 75°57’W), 21–24.II.2006, coll. N. Kluge. Paratypes: the same locality and collector, 25.II.2006: 1 L-S-I ♀, 18 larvae.

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 479–486 ). 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. In last instar larva, tibiae more or less darkened with brown or blackish, darker than femora (this coloration at first appears on fore leg, than on other legs). In larvae of various instars, abdomen with more or less expressed transverse brown or gray stripes on posterior margins of all or some terga.

SHAPE AND SETATION. Clypeus parallel-sided; labrum 1.2–1.4 times wider than clypeus ( Figs 481, 485 ). 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 16–17 pectinate setae in apical-ventral row.

Femora: Stout setae on anterior surface narrowed distally or parallel-sided, apically truncated ( Fig. 487 ). Irregular row of hairs near inner margin absent on fore femur, present on middle and hind femora.

Fore tibia ( Fig. 488 ): outer hairs form two irregular rows; inner-anterior row of recurved hairs absent; inner-anterior row of stout setae represented by few (2–3) 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).

Hind tibia ( Figs 489–490 ): outer-anterior row of stout setae consists of two clearly different types of stout setae: numerous shorter blunt ones and several long spoon-like ones; outer-posterior row of stout setae consists of blunt stout setae of various lengths; 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, parallelsided and truncated.

Claws with 6–7 denticles on rigid portion, with or without minute denticles on articulatory portion.

Tergalii ( Figs 503–506 ): 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.

Male genitalia in last larval instar ( Fig. 498 ): protogonostyli long and separated one from another by deep emargination. Each protopenis lobe apically wide, with gonopore-bearing process sharply projected caudally and located near median margin; gonopore opened caudally-laterally.

Subimago. CUTICULAR COLORATION. Cuticle mostly light ocher, nearly colorless. Flagellum of antenna darker, light brown. Mesonotum partly brown, with dark brown antelateroparapsidal suture, colorless area on posterior scutal protuberance and colorless achromozones; medioscutal chromozone somewhat darker than submedioscutal chromozone ( Fig. 497 ). Thoracic pleura with some sclerites light brownish. On all legs femur mostly light ocher, bordered by darker brown on outer and inner margins and apically; tibia and tarsus light brown. Cuticle of wings colorless, microtrichia brown. Abdominal terga very light brownish, sterna colorless.

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. Unknown. Based on male subimago extracted from mature larva, following imaginal features can be reported.

Head brown. Antenna with scapus and flagellum ocher, pedicellus dark brown. Dorsal eyes contiguous medially, grayish.

Legs of all pairs with femur and tibia uniformly dark brown; tarsus of fore leg with each segment proximally dark brown, distally ocher; tarsus of middle and hind legs light brownish.

Abdominal hypodermal coloration ( Fig. 495 ): Terga with posterior margins narrowly bordered by grayishbrown; tergum I mostly brown; terga II–VI mostly ocher, each with pair of small, diffusive, transverse reddish-andbrown marks laterally; terga VII–X medially reddish-brown, laterally whitish; tergum VIII with pair of longitudinal lateral brown stripes, laterally narrowly bordered by brown; tergum IX with pair of smaller longitudinal lateral brown stripes. Abdominal sterna ocher with grayish nerve ganglia; sternum VIII with pair of longitudinal reddish stripes and brown maculae anteriad and posteriad of them; sternum IX tinged with reddish antero-laterally. Caudalii in proximal part dark brown with each 4th segment lighter, in middle part with alternated darker and lighter brown segments; all joinings darker brown.

Genitalia ( Figs 496 , 499–501 ). Long segments of gonostyli (initial 1st+2nd segments) with intensive dark brown hypodermal coloration, both apical segments without it. Dorsal extension of styliger very long, parallelsided, truncated apically. Telopenes in form of spear-like rolls, long and straight; judging by projection laterad of spear-like roll ( Fig. 501 ), imaginal penis with well-developed ears.

Female imago ( Figs 493–494 ). Head brown. Antenna with scapus and flagellum ocher, pedicellus dark brown. Pronotum brown with darker and lighter areas, propleura and prosternum ocher with brown. Mesonotum light brown; mesothoracic pleural sclerites, basisternum, furcasternal median impression and furcasternal protuberances brown, other areas ocher. Metathorax brown with ocher.

Legs of all pairs with femur and tibia uniformly dark brown, tarsus light brownish. In specimen reared from larva, relation of fore, middle and hind femora to fore wing length 70:67:85:310; proportions femur/tibia/tarsomeres on fore leg 70:77:2:7:6:5:9; on middle leg 67:72:2:3:3:2:8; on hind leg 85:82:2:3:3:2:8.

Fore wing with longitudinal and cross veins ocher-brownish; costal brace and adjacent parts of C and Sc dark brown. Costal cross veins proximad of bulla few, light ocher-brownish 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 prominent; proximal part of hind wing brown ( Fig. 507 ).

Abdominal terga dorsally light brown, laterally with ocher; sterna mostly ocher; uromere VII with posterior part of sternum dark brown; uromere VIII with lateral parts of tergum and sternum brown; uromere IX with lateral parts of tergum and posterior part of sternum brown.

Eggs ( Figs 508–509 ). Mostly barrel-shaped. Each KTC surrounded by ring-like cover with smooth surface; in some areas of egg ring-like covers smoothed out, being indistinguishable from surrounding surface. Other chorion rugose, nearly without protuberances.

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

Comparison. Besides the new species Th. nigripes sp. n., femora and tibiae of all legs in imaginal and subimaginal stages are uniformly dark brown only in Th. niger sp. n. and Th. nigrabdominalis sp. n. Male Th. nigripes sp. n. differs from both of them by the longer and wider dorsal extension of styliger ( Fig. 499 ); this difference is expressed beginning from the early stage of development in last-instar larva—compare Fig. 502 and Fig. 477 . Besides this, male of Th. nigripes sp. n. differs from Th. niger sp. n. and Th. nigrabdominalis sp. n. by the contrastingly different coloration of abdominal terga II–VI and VII–X ( Fig. 495 ). Male and female imagines and subimagines of Th. nigripes sp. n. also differ from Th. niger sp. n. by presence of dark macula close to costal brace and by absence of coloration in costal and subcostal fields of fore wing ( Fig. 493 ). Larva of Th. nigripes sp. n. differ both from Th. niger sp. n. and Th. nigrabdominalis sp. n. by uniformly brown coloration of abdominal terga.

Figures

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 491–497. Thraulodes nigripes sp. n. 491–492, fore and middle legs of female imago; 493–494, female imago in dorsal and lateral view; 495, abdominal terga and sterna of male subimago extracted from larva; 496, genitalia of male subimago extracted from larva; 497, right half of subimaginal exuviae of mesonotum (495–496, holotype).

FIGURES 498–507. Thraulodes nigripes sp. n. 498, larval protogonostyli and protopenis; 499, subimaginal styliger and gonostyli extracted from larva; 500–501, subimaginal penis inside larval protopenis in ventral and dorsal view; 502, larval protogonostyli with subimaginal gonostyli and styliger at earlier stage of development; 503–506, tergalii I, III, VI and VII (498–501, 503–506, holotype).

FIGURES 508–509. Thraulodes nigripes 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.

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).

FIGURES 474–478. Thraulodes nigrabdominalis sp. n. 474, genitalia of male imago in ventral view; 475, their subimaginal exuviae; 476, hind wing; 477–478, protogonostyli and protopenis of presumably associated larva, with subimaginal gonostyli and styliger at early stage of development shown by interrupted line (474–476, holotype).