Thraulodes marreroi Chacon et al. 1999

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 : 61-68

7. Thraulodes marreroi Chacon et al. 1999

( Figs 208–249 )

Thraulodes marreroi Chacon, Segnini & Dominguez 1999: 255 , figs 13–18 (♂ imago).

Material examined. PANAMA, Provincia de Colon, Parque Nacional Soberania, Rio Frijoles , camina del oleoducta, 11.II.2018, coll. N. Kluge & L. Sheyko, 9–11.II.2018: L-S-I ♂, 1 L-S-I ♀, 2 S-I ♂, 1 I ♂, 5 S ♂, 1 S-I ♀, 3 I ♀, 1 S ♀, 9 larvae.

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 208–219 ). Dorsal side of head, thorax and abdomen mostly brown with characteristic blanks: pronotum bordered by light laterally, with blanks of characteristic composite form; fore protoptera mostly light, with dark lines corresponding to convex longitudinal veins; abdominal terga with blanks on lateral parts, terga IV–V (or at least tergum V) with blank medially, terga VIII–X partly light. Femora with brown areas and blanks; tibiae and tarsi uniformly light or uniformly brownish.

HYPODERMAL COLORATION. Abdominal terga, besides cuticular coloration (see above) often with paired transverse or round blackish spots corresponding to midway gray spots of imago ( Fig. 227 ). Tergalii gray, tracheae black ( Figs 220–226 ).

SHAPE AND SETATION. Clypeus parallel-sided; labrum 1.3 wider than clypeus ( Figs 210, 216 ). Labrum ( Figs 208–210 ) widest at midlength, with narrow median emargination exposed ventrally; if all 5 denticles present, bottom of median emargination formed by 3 narrow denticles and its sides formed by 2 wider denticles (some denticles can be fused, smoothed out or absent); anterior transverse setal row wider than all 5 denticles, in its median part represents field of irregularly situated setae ( Fig. 209 ). Maxilla with 13–15 pectinate setae in apical-ventral row.

Femora: Stout setae on anterior surface parallel-sided and blunt ( Fig. 228 ). Irregular row of hairs near inner margin absent on fore femur, represented by few setae on middle femur, sparse on hind femur.

Fore tibia ( Fig. 229 ): outer hairs arranged irregularly; 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 2 rows, setae of anterior row pectinate, setae of posterior row longer and more finely pectinate.

Hind tibia ( Figs 230–231 ): outer-anterior row of stout setae consists of two clearly different types of stout setae: numerous very short blunt ones and occasional long spoon-like ones; outer-posterior row of stout setae consists of blunt stout setae of moderate length; posterior hairs located between these rows, form one irregular row (besides row of hairs posteriad of outer-posterior row of stout setae); stout setae of inner-anterior row short, widened distally and truncated.

Claws with 8–10 denticles on rigid portion, with several minute denticles on articulatory portion.

Tergalii ( Figs 220–226 ): wide; on both lamellae main trachea without branches; 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. 244 ): protogonostyli separated one from another by moderately deep emargination. Each protopenes lobe with gonopore-bearing process bent laterally; gonopore opened laterally.

Subimago ( Figs 235 , 243 ). CUTICULAR COLORATION. Cuticle with colorless and light brownish areas. Flagellum of antenna brownish. Pronotum colorless. Mesonotum with lighter and darker brown areas; chromozone of medioscutum brown, chromozone of submedioscutum contrastingly lighter brownish ( Fig. 235 ). On all legs femur in proximal 2/3 colorless, gradually becomes brown toward apex; tibia brownish; tarsus lighter brownish. Cuticle of wings colorless, microtrichia light brownish. Abdominal terga and sterna mostly colorless, posterior terga diffusively tinged with brownish at median part. Gonostyli and caudalii light brownish.

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 232–234 ). Head brown with ocher. Antennae with scapus ocher, pedicellus brown, flagellum ocher. Dorsal eyes contiguous medially, dull orange.

Prothorax either nearly entirely ocher with pair of dark brown spots above coxa, or with brown median area of pronotum ( Fig. 234 ). Lateral sides of pterothorax ocher with brown. Ventral side of pterothorax partly ocher; me- sothoracic episterna and furcasternal protuberances brown; basisternum and median furcasternal impression lighter brown.

Cuticle of legs mostly colorless; on fore leg apex of femur, base and apex of tibia with cuticle brown; on middle and hind legs apex of femur lighter brownish. Legs with following hypodermal pigmentation on whitish background: Fore femur with multicolored pre-apical band, occupying distal 0.4 of femur; pre-apical band mainly orange-brown, proximally bordered by blackish-brown, on inner side with blackish-brown longitudinal stripe. Middle and hind femora with multicolored pre-apical band within apical 1/3 of femur; pre-apical band mainly orange-brown, proximally bordered by blackish-brown, on inner side with blackish-brown longitudinal stripe. In selected individual, relation of fore femur to fore wing length 48:225; proportions femur/tibia/tarsomeres on fore leg 48:75:3:21:16:10:7; on middle leg 48:51:2:3:3:2:6; on hind leg 58:60:2:3:3:2:6.

Fore and hind wings with dark brown macula on costal brace and bases of Sc and R; longitudinal and cross veins colorless (proximal coloration of fore and hind wings appears during larval development and present both in subimago and imago). Costal cross veins proximad of bulla either absent, of few, colorless and very thin, so that visible only under high magnification (as in Fig. 142 ). Pterostigmatic cross veins not dense, perpendicular to longitudinal veins or slightly oblique, non-branched ( Chacon et al. 1999: fig. 13). Hind wing with prominent costal projection ( Fig. 245 ).

Abdominal hypodermal coloration: Tergum I brownish. Terga II–V whitish, translucent, tinged with orange at median areas; terga VI–VII orange; tergum VIII anteriorly-medially orange and posteriorly-laterally whitish; terga XI–X orange; each tergum II–VIII with a pair of gray midway spots; pleura with gray stigmatic spots. Abdominal sterna I–VI whitish, sterna VII–IX whitish with light orange. Caudalii with one partly black segment alternated with 3 white segments.

Genitalia ( Figs 237–243 ): Styliger and gonostyli light ocher; penis brownish. Dorsal extension of styliger conic. Penis lobes relatively short, swollen ventrally and greatly widened toward apex, being at apex as wide as styligeral cavity. Telopenes in form of spear-like rolls, long, curved, attached on caudal sides of penis lobes, directed medially-ventrally and bent caudally, with groove opened laterally.

Female imago ( Figs 246–247 ). Abdominal terga II-IV medially orange-brown; in other respects coloration similar to that of male.

Eggs ( Figs 248–249 ). Mostly barrel-shaped. Each KTC surrounded by thick ring-like cover. Other chorion with evenly dispersed protuberances.

Dimension. Fore wing length (and approximate body length) 5–6 mm.

Distribution. Venezuela ( Chacon et al. 1999) and Panama (this study).

Comments. Male imago of Th. marreroi is very similar to Th. schlingeri : it has the same coloration and similar penis structure with long and sinuous telopenes bent ventrally. In the original description of Th. marreroi , which was based on male imagines only, its comparison with Th. schlingeri was not given. Comparison of the new material from Panama and from the type locality of Th. schlingeri in Peru with the original descriptions of Th. marreroi and Th. schlingeri allows us to conclude that their male imagines differ by shape of penis, which in Th. marreroi is not so wide as in Th. schlingeri , and by coloration of caudalii. Larva of Th. marreroi differs from Th. schlingeri by the absence of side tracheal branches on tergalii. Egg of Th. marreroi differs from Th. schlingeri by evenly dispersed protuberances, not concentrated around KTCs.

Figures

FIGURES 208–231. Thraulodes marreroi. 208, margin of labrum with focus on posterior transverse setal row; 209, the same with focus on anterior transverse setal row (represented by field of irregularly situated setae) (arrows show four sensilla separating three denticles). 210–215 and 216–219, larval exuviae of two different specimens at the same magnification; 220–226, tergalii I–VII; 227, immature larva (with ocher and whitish cuticular coloration and blackish paired hypodermal markings on abdomen); 228, anterior side of hind femur; 229, anterior side of fore tibia; 230, hind tibia with focus on outer-posterior row of stout setae; 231, the same with focus on outer-anterior and inner-anterior rows of stout setae.

FIGURES 232–239. Thraulodes marreroi. 232–234, male imago in dorsal, ventral and lateral view; 235, left half of subimaginal exuviae of mesonotum; 236–239, male imaginal genitalia in apical, dorsal ventral and lateral view.

FIGURES 240–245. Thraulodes marreroi. 240, genitalia of male imago in lateral view; 241, apex of penis in dorsal view; 242, genitalia in ventral view; 243, sibimaginal exuviae of styliger, gonostyli and telopenes; 244, larval protogonostyli and protopenis; 245, hind wing.

FIGURES 246–247. Thraulodes marreroi, female imago.

FIGURES 248–249. Thraulodes marreroi, eggs.

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).