Thraulodes flavus, 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 : 85-91

11. Thraulodes flavus sp. n.

( Figs 350–378 )

Etymology. Allusion to yellow color of imago.

Material examined. Holotype: L-S-I ♂ {specimen [XII](10)2018}, PANAMA, Provincia de Bocas del Toro, Bosque protector Palo Seco, Altos del Valle , Rio Buris (8°47’37’’N, 82°11’35’’W), 27.I.2018, coll. N. Kluge & L. Sheyko. Paratypes: the same locality and collectors, 24–28.I.2018: 8 I ♂ and 12 I ♀ (at light), 1 L /S ♀, 4 larvae.

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 350–356 ). Dorsal side of head, thorax and abdomen mostly brown with few blanks: pronotum bordered by light laterally, with or without other blanks; abdominal terga with blanks on lateral parts, area mediad of tergalii attachments nearly unicolor brown, terga VIII–IX with diffusive blank medi- ally. Fore protoptera with indistinct darkenings corresponding to dark maculae on imaginal wings. Femora mostly brown, with blanks; tibiae and tarsi uniformly light brown.

HYPODERMAL COLORATION. Abdomen without blackish hypodermal markings. Tergalii yellowish with gray ( Fig. 361 ).

SHAPE AND SETATION. Clypeus widened distally; labrum 1.3–1.45 times wider than clypeus ( Fig. 351 ). 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 and blunt ( Fig. 359 ). Irregular row of hairs near inner margin present on all femora ( Fig. 364 ).

Fore tibia ( Fig. 360 ): outer hairs form two irregular rows; inner-anterior row of recurved hairs absent; inneranterior row of stout setae represented by few (4–7) stout setae in proximal part of tibia; inner field of stout pointed setae sparse, denser on middle 1/3 of tibia, consists of pointed setae of subequal length, among which bipectinate setae form 1 row, and non-pectinate setae form 2 irregular rows posteriad of it.

Hind tibia ( Fig. 357–358 ): both outer-anterior and outer-posterior rows of stout setae consist of more or less pointed 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, narrowed distally and truncated.

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

Tergalii ( Figs 350 , 361 ): each lamella slender, tracheae without side branches.

Male genitalia in last larval instar ( Fig. 375 ): protogonostyli separated one from another by deep emargination. Each protopenis lobe with gonopore-bearing process located near median margin; gonopore opened caudally.

Subimago ( Figs 368, 369 , 374 ). CUTICULAR COLORATION. Cuticle mostly colorless. Flagellum of antenna brownish. Pronotum tinged with light brownish laterally. Mesonotum with antelateroparapsidal suture contrastingly colored with dark brown, some other sutures shed with brownish; chromozones as colorless as achromozones ( Fig. 368 ). On fore leg femur colored with dark brown on outer side and close to apex, tibia brown at very base and light brownish apically, tarsal segments 2–4 light brownish ( Fig. 369 ). Middle and hind legs with tibiae and tarsi slightly colored with ocher. Cuticle of wings colorless, microtrichia light brownish. Other cuticle of body, legs, caudalii and gonostyli 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 ( Figs 365–366 ). Coloration yellow with orange, with contrasting black markings.

Head yellow with black, antennae entirely yellow. Dorsal eyes contiguous medially, dull orange. Pronotum yellow with pair of large black maculae laterally and narrower black line medially. Mesothorax and metathorax yellow, with black maculae on pleura.

Cuticle of legs mostly colorless; on fore leg, apex of femur and base of tibia with cuticle light brown. Legs with following hypodermal pigmentation on ocher background: Fore femur orange with dark brown apex; posterior side with longitudinal blackish-brown macula at middle; inner side with blackish-brown macula near base and blackish-brown stripe on distal 2/3. Fore tibia orange with black apex. Fore tarsus with middle areas of 2nd-4th segments brown. Middle and hind femora with 2 wide, diffusive, orange bands, one near base and another at apex; proximal band with longitudinal blackish-brown macula on posterior side near middle of femur; apical band with longitudinal blackish-brown stripe on posterior-inner margin. Middle and hind tibiae with small brown apical spot; tarsus with orange spots on 2nd–5th segments. In holotype, relation of fore femur to fore wing length 85:355; proportions femur/tibia/tarsomeres on fore leg 85:120:3:38:30:20:10; on middle leg 82:108:3:6:5:4:9; on hind leg 95:115:3:6:5:4:9.

Fore wing with oblique cross veins in costal field, both proximad and distad of bulla; pterostigmatic cross veins dense and partly anastomosed. Costal field yellow, with cross veins proximad and posteriad of bulla bordered by brown. Subcostal field orange with apex brown. Orange or brownish transverse stripe posteriad of costal brace. Cross vein near bulla and furcation of MA bordered by brown. Longitudinal veins C, Sc and RA orange, distal part of RA brown; other longitudinal veins ocher. Cross veins posteriad of RA brown. Hind wing without coloration ( Fig. 376 ). Coloration of fore wing partly appears during larval development, being in subimago less contrasting than in imago.

Abdomen whitish-yellowish, with diffusive narrow grayish bands on posterior margins of terga I–X, with oblique lateral orange streaks on terga II–VI; terga VII and IX–X mostly orange; stigmatic spots absent. Caudalii ocher, each segment proximally dark (brown or orange); segments with longer and shorter dark portions alternate.

Genitalia ( Figs 370–374 ): Styliger, gonostyli and penis light ocher. Dorsal extension of styliger small and prominent. Penis lobes widely divergent; each lobe gradually widened apically, without lateral pouch. Apico-lateral area forming well-expressed ear; ventro-apical plate moderately developed, hiding base of spear from ventral view. Telopenes in form of spear-like rolls, directed medially-caudally-ventrally, nearly straight, with groove opened dorsal-laterally ( Fig. 372 ).

Female imago ( Fig. 367 ). Coloration of head, thorax, wings, legs and caudalii as in male. Dorsal side of head varies from entirely yellow to yellow with wide black transverse band connecting eyes and all three ocelli. Coloration of abdomen similar to that of male, but with tergum VII not colored with orange.

Eggs ( Figs 377–378 ). Mostly barrel-shaped. Each KTC surrounded by ring-like cover. Chorion between KTCs with rugose ridges forming hexagonal or pentagonal cells, with one KTC in each cell.

Dimension. Fore wing length (and approximate body length) 8.5–10 mm.

Comparison. Eggs with net-like relief, besides Th. flavus sp. n., were reported only for Th. packeri Traver & Edmunds 1967 and some unnamed species from Brazil, Chile and Costa Rica ( Traver & Edmunds 1967). The male imago of Th. flavus sp. n. differs from Th. packeri by the entirely light yellow color of mesonotum (in contrast to pale reddish brown with dark and black in Th. packeri ), the yellow coloration of costal and subcostal fields of fore wing, absence of black or dark brown markings on abdomen, wider dorsal extension of styliger and absence of lateral pouches on penis.

Figures

FIGURES 350–360. Thraulodes flavus sp. n. 350–356, larval exuviae at the same magnification: 350, abdominal terga; 351– 353, parts of head with labrum and mandibles; 354, left half of pronotum and mesonotum; 355–356, fore and hind legs; 357, hind tibia with focus on outer-posterior row of stout setae; 358, the same with focus on outer-anterior and inner-anterior rows of stout setae; 359, anterior side of fore femur; 360, anterior side of fore tibia (350–356, 359–360, holotype).

FIGURES 361–364. Thraulodes flavus sp. n. (holotype). 361, tergalii; 362–363, distal segment of maxillary palp in ventral and dorsal view; 364, hind femur in anterior view.

FIGURES 365–370. Thraulodes flavus sp. n. 365–366, male imago in lateral and dorsal view; 367, female imago; 368, left half of subimaginal exuviae of mesonotum; 369, subimaginal exuviae of fore leg of male; 370, genitalia of male imago (368–370, holotype).

FIGURES 371–376. Thraulodes flavus sp. n. 371, genitalia of male imago in lateral view; 372, apex of penis in dorsal view; 373, genitalia of male imago in ventral view; 374, their subimaginal exuviae; 375, larval protogonostyli and protopenis; 376, hind wing (372–376, holotype).

FIGURES 377–378. Thraulodes flavus 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.