Thraulodes zonalis Traver & Edmunds 1967

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 : 79-83

10. Thraulodes zonalis Traver & Edmunds 1967

( Figs 317–349 )

Thraulodes zonalis Traver & Edmunds 1967: 383 , figs 25, 41 (♂ imago and presumably associated larva); Allen & Brusca 1978: 421, fig. 26 (presumably associated larva).

Material examined. PANAMA, Provincia de Coclé, El Valle de Anton, Rio Anton , (8°35’N, 80°07’W), 3–5.II.2018, coll. N. Kluge & L. Sheyko: 1 L-S-I ♀, 1 L /S ♂, 2 larvae.

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 317–320, 328–331 ). Dorsal side of head, thorax and abdomen mostly brown with few blanks: pronotum bordered by light laterally, without other blanks; abdominal terga with blanks on near tergalii bases, area mediad of them nearly unicolorous brown. Femora mostly brown with proximal and preapical blanks; tibia brown; tarsus brown with base and apex lighter.

HYPODERMAL COLORATION ( Fig. 331 ). Abdominal terga I–IX with transverse band on posterior margins; terga II–V also with pair of brown spot. Tergalii gray with yellowish ( Figs 321–327 ).

SHAPE AND SETATION. Clypeus widened distally; labrum 1.3–1.4 times wider than clypeus ( Fig. 318 ). 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 15–16 pectinate setae in apical-ventral row.

Femora: Stout setae on anterior surface parallel-sided and blunt ( Fig. 333 ). Irregular row of hairs near inner margin absent on fore femur, present on middle and hind femora.

Fore tibia ( Fig. 334 ): outer hairs form two irregular rows; inner-anterior row of recurved hairs absent; inneranterior row of stout setae absent or represented by single blunt stout seta near tibia base; inner field of stout pointed setae dense (i.e. setae longer than distances between them, about 3 setae in cross section), setae of most anterior row shorter than others, bipectinate or dentate.

Hind tibia ( Figs 335–336 ): outer-anterior row of stout setae consists of two clearly different types of stout setae: numerous short rounded ones and several long spoon-like ones; outer-posterior row of stout setae consists of blunt and spoon-like 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 short, widened distally and truncated.

Claws with 5–7 denticles on rigid portion, with several minute denticles on articulatory portion.

Tergalii ( Figs 321–327 ): of moderate width; 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 ( Figs 346–347 ): protogonostyli separated one from another by deep emargination. Each protopenes lobe smoothly stretched to gonopore-bearing process located near median margin; gonopore opened caudally.

Subimago. CUTICULAR COLORATION ( Figs 337–338 ). Cuticle brown with lighter brownish and colorless areas. Pronotum light brow. Mesonotum mostly brown, with darker brown antelateroparapsidal and lateroparapsidal sutures, with colorless oblique stripe on posterior scutal protuberance; chromozones of medioscutum and submedioscutum equally colored by brown; achromozones of medioscutum and submedioscutum contrastingly colorless. On all legs femur mostly light, bordered by brown on outer and inner margins, with apex brown; tibia brownish; tarsus lighter brownish. Wings look gray due to blackish microtrichia and small brown ring around base of each microtrichion. Abdominal terga, sterna 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. Described by Traver & Edmunds (1967). Coloration as in female (see below).

Female imago ( Figs 338–342, 344–345 ). Head and thorax dark brown.

Cuticle of legs mostly colorless; on fore leg apex of femur and base of tibia with cuticle brown; on middle and hind legs apex of femur with lighter brownish. Legs with following hypodermal pigmentation on whitish background: Fore femur entirely pigmented, with proximal part blackish-brown and distal part reddish-brown, with blackish stripe along inner margin. Fore tibia mostly reddish-brown, basally and apically darker brown. Fore tarsus light brown with non-pigmented joinings. Middle femur with gray-brown spot on posterior side close to base, larger brown spot on anterior side more distally and multicolored pre-apical band occupying distal half of femur both on anterior and posterior sides; pre-apical band mainly reddish-brown, proximally bordered by blackish brown. Hind femur with large basal brown spot on anterior side, occupying most part of proximal half of femur beginning from its base, and with multicolored pre-apical band as on middle femur. On middle and hind legs tibia mostly non-pigmented, with brown spots near base (close to patella-tibial suture) and on apex; tarsus with small brown spots on 3rd, 4th and 5th tarsomeres. In reared individual, relation of fore femur to fore wing length 80:350; proportions femur/tibia/tarsomeres on fore leg 80:80:4:7:7:5:10; on middle leg 80:75:4:5:4:3:9; on hind leg 95:90:4:5:4:3:9.

Fore wing with dark brown band crossing costal brace. Longitudinal veins ocher or light brown; cross veins light brown, in anterior part of wing narrowly bordered by light brown; costal cross veins proximad of bulla few and very thin, bordered by brown near subcostal vein ( Figs 344–345 ). Pterostigmatic cross veins not dense, oblique, non-branched (as in male, Traver & Edmunds 1967: fig. 25). Hind wing short, with costal projection prominent; proximal part of hind wing brown ( Fig. 342 ).

Abdomen brown with poorly expressed darker brown midway spots on terga III–V.

Eggs ( Figs 348–349 ). Mostly barrel-shaped. Each KTC without ring-like cover, spirally coiled threads being exposed. Other chorion with evenly dispersed protuberances.

Dimension. Fore wing length (and approximate body length) 6–8 mm.

Distribution. Panama ( Traver & Edmunds 1967; this study).

Comments. The original description of Th. zonalis was based on male imagines ( Traver & Edmunds 1967). The male subimago, extracted from larva, has the same hypodermal coloration, especially characteristic coloration of legs (as in female—Figs 339–341) and abdomen ( Fig. 343 ).

In the original description, coloration of proximal half of middle femur is characterized as «2 dark spots within this pale basal area, arranged in tandem», and coloration of hind femur—as «femur III twice-banded...» ( Traver & Edmunds 1967: 383). Actually, each of these femora has only one true band girdling the femur, this is the pre-apical one; on the proximal half of middle and hind femora dark pigment does not form bands girdling the femur, but forms separated spots, each of which is located on one side of the femur only. On the proximal half of middle femur, there are 2 dark spots located on different sides of the femur (more proximal spot—on posterior side, and more distal spot—on anterior side), so that they look as «tandem» only if the femur is translucent. On the hind femur the proximal large spot is located on the anterior side only.

According to the original description, male imago of Th. zonalis has «most cross veins indistinct ... In apical area C, Sc, and R 1 somewhat thickened; 3–5 stigmatic veins, these on 2 or 3 in subcostal space also thickened» ( Traver & Edmunds 1967: 383, fig. 25). This is the same as in male imago of Th. fascipennis ( Fig. 298 ). Female imago of Th. zonalis described here for the first time, has somewhat different coloration of fore wing, with all cross veins colored. Possibly, this is a sexual dimorphism in wing coloration.

Figures

FIGURES 317–336. Thraulodes zonalis. 317–331, larval exuviae at the same magnification; 332, young larva with light cuticle and well visible blackish hypodermal markings; 333, anterior side of hind femur; 334, anterior side of fore tibia; 335, hind tibia with focus on outer-posterior row of stout setae; 336, the same with focus on outer-anterior and inner-anterior rows of stout setae.

FIGURES 337–345. Thraulodes zonalis. 337, left half of subimaginal exuviae of mesonotum; 338, female imago with its subimaginal exuviae; 339–341, fore, middle and hind legs of female imago; 342, hind wing; 343, abdominal terga and sterna of male subimago extracted from larva (sterna VIII–IX with larval cuticle); 344–345, anterior-proximal part of fore wing.

FIGURES 346–347. Thraulodes zonalis. 346, larval protogonostyli and protopenis in dorsal view with developing subimaginal gonostyli and penis; 347, optic section of through protopenis with developing penis. Abbreviations: gd, larval cuticle of gonoduct; tp, subimaginal telopenis.

FIGURES 348–349. Thraulodes zonalis, 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 297–308. Thraulodes fascipennis sp. n. 297, left half of subimaginal exuviae of mesonotum; 298–300, male imago in dorsal, ventral and lateral view; 301, abdominal terga and sterna of male imago; 302–303, male imaginal genitalia in ventral and lateral view; 304, male imaginal penis; 305–307, fore, middle and hind legs of male imago; 308, subimaginal exuviae of fore leg (301, holotype).