Thraulodes alboniger, 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 : 120-127

17. Thraulodes alboniger sp. n.

( Figs 543–590 )

Etymology. Allusion to coloration of male imago, which is mainly white with black.

Material examined. Holotype: L-S-I ♂ {specimen [ XX](1)2013}, PERU, Region Loreto, Provincia Ucayali, Pampa Hermosa (7°12’S, 75°22’W), 18.VIII.2013, coll. N. Kluge & L. Sheyko. Paratypes: the same locality and collectors, 9–21.VIII.2013: 1 L /S ♀, 7 larvae; river Ucayali between Orellana and Contamana , 19.II.2006 (at light on boat), coll. N. Kluge: 5 I ♂; 17 km NNE Contamana, Aguas Termales (7°11’S, 74°57’W), 26.VII–4.VIII.2013, coll. N. Kluge & L. Sheyko: 1 L /S ♂; San Alejandro (8°50’S, 75°13’W), 26.VIII.2013, coll. N. Kluge & L. Sheyko: 1 I ♂ .

Descriptions.

Larva. CUTICULAR COLORATION ( Figs 544–550 ). Dorsal side of head brown with more or less expressed paired and unpaired blanks on frons and occipit. Pronotum and mesonotum brown with blanks of characteristic shape ( Fig. 546 ); fore protopteron with veins lighter than background. Femur with 2 brown zigzag transverse bands, either separated ( Fig. 548 ), or fused ( Fig. 550 ); tibia with 2 wide brown bands (proximal and middle); tarsus with middle brown band. Abdominal terga brown; II–IX with pair of oblique lateral blanks; terga V and VIII also with pair of submedian blanks.

HYPODERMAL COLORATION. Larvae of various instars, besides cuticular coloration (see above) with following blackish hypodermal markings ( Fig. 543 ): pair of large rhomboid longitudinal maculae on pronotum; several small maculae on mesothoracic tergum; maculae on mesothoracic and metathoracic pleura; apical macula on each femur and preapical macula on fore and hind femur; median longitudinal macula on each or some of abdominal terga; two pairs of small lateral maculae on abdominal terga I–VII; transverse band on posterior margins of terga I–IX. Among these maculae, at lest the paired maculae on pronotum are well expressed on all specimens examined. Tergalii gray.

SHAPE AND SETATION. Clypeus parallel-sided; labrum 1.15–1.25 times wider than clypeus ( Fig. 544 ). Labrum widest at midlength, with lateral sides rounded; fore margin visible in dorsal view, without median emargination, shallowly concave, with all 5 denticles wide; anterior transverse setal row regular, as wide as anterior margin, subequal to poster transverse setal row ( Fig. 563 ). Maxilla with 10 pectinate setae in apical-ventral row. Mandibles with outer margin shallow, with two concavities ( Fig. 545 ).

Femora: Stout setae on anterior surface pointed ( Fig. 560 ). Row of hairs near inner margin absent on fore and middle femora, absent or represented by a few setae on hind femur.

Fore tibia ( Fig. 558 ): outer hairs form two irregular rows; inner-anterior row of recurved hairs absent; inneranterior row of stout setae represented by few (4–5) stout blunt setae in proximal part of tibia; inner field of stout pointed setae reduced: its setae as parse and small as on middle and hind legs, only near apex of tibia several longer and dense setae of this row present, including subapical inner-posterior row of arched pointed setae.

Hind tibia ( Figs 561–562 ): each of three rows of stout setae—outer-anterior, outer-posterior and inner-anterior ones—consists of pointed stout setae; outer-anterior row, besides this, contains one or more long spoon-like stout seta(e); hairs located between outer-anterior and outer-posterior rows, form mostly one irregular row (besides row of hairs posteriad of outer-posterior row of stout setae).

Tarsus of hind leg with stout setae on inner and outer margins.

Claws with 4 denticles on rigid portion, often without denticles on articulatory portion.

Tergalii ( Figs 551–557 , 585–588 ): wide; on both lamellae main trachea arched repeating outline of anal margin, with branches directed toward costal margin; dorsal lamella oval, widest in distal part, apically abruptly turned to slen- der apical filament; ventral lamella widest near base, gradually narrowed toward apex, with slender apical filament.

Male genitalia in last larval instar ( Fig. 584 ): protogonostyli long and widely separated, with few small hairs. Each protopenis lobe with gonopore-bearing process bent laterally; gonopore opened caudally-laterally.

Subimago ( Figs 569, 577 , 581 ). CUTICULAR COLORATION. Cuticle mostly colorless. Flagellum of antenna brownish. Mesonotum with antelateroparapsidal suture contrastingly colored with dark brown, some other sutures shed with brown; chromozones colorless ( Fig. 577 ). Fore leg with tarsal segments 2–4 colored with light brownish. Middle and hind legs with tibiae and tarsi slightly colored with light brownish. Cuticle of wings colorless, microtrichia light brownish. Other cuticle of body, legs, gonostyli and caudalii 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 570–576 ). Coloration contrasting, with white and black areas.

Head dorsally black, frons whitish; antennal scapus white, pedicellus black, flagellum white. Dorsal eyes contiguous medially, dull orange.

Pronotum whitish or pale yellowish, with pair of large, contrasting black maculae on pronotum, black median stripe between them and black stripe on posterior margin; sometimes with pair of black spots on pleura ( Fig. 574 ). Mesonotum with cuticle brown ( Fig. 575 ), sometimes with black hypodermal coloration ( Fig. 574 ). Mesothorax always with black maculae on episternum, on pleuron between pleural suture and subalar sclerite, on lateropostnotum and on tip of scutellum; its basisternum and furcasternum always non-pigmented. Metathorax always with pair of large black maculae on pleura; is sternum always non-pigmented.

Legs with very contrasting black and brown markings. Cuticle of legs mostly colorless; on fore leg apex of femur and base of tibia with cuticle brown, middle part of tibia light brown. Legs with following hypodermal pigmentation on whitish background: Fore femur with black apical band; either with blackish-brown and purple spots proximad of it ( Fig. 574 ), or without them ( Fig. 575 ). Fore tarsus with proximal parts of 2nd–4th tarsomeres black or brown. Middle femur with black apical spot. Hind femur with black apical spot and larger black pre-apical band. Middle and hind tarsi with proximal parts of 2nd–3rd segments black. In holotype, relation of fore femur to fore wing length 56:245; proportions femur/tibia/tarsomeres on fore leg 56:68:2:22:26:9:7.

Fore and hind wings with membrane and veins colorless,with contrasting black spot on junction of costal brace with Sc and R (proximal coloration of fore and hind wings appears during larval development and present both in subimago and imago). Fore wing with or without cross veins in costal field proximad of bulla. Pterostigmatic cross veins few, perpendicular to longitudinal veins, non-branched ( Fig. 570 ). Hind wing with costal projection shallow ( Fig. 578 ).

Abdomen mostly white, with contrasting black hypodermal markings on terga; tergum VII always with pair of large black maculae laterally; following black markings present or absent on some or all terga: median longitudinal stripe, transverse stripe on posterior margin, pair of small sublateral spots, pair of small lateral spots, pair of stigmatic spots. Terga VII–X, besides black spots, with more or less developed red or yellow hypodermal coloration. Caudalii with segments alternated as following: black; white; white with longitudinal black stripe; white.

Genitalia ( Figs 579–582 ): Styliger, gonostyli and penis light ocher. Dorsal extension of styliger not separated from styliger, either rather wide ( Fig. 579 ) or smoothed out ( Fig. 580 ). 1st segment of gonostylus with prominent medio-distal angle; 2nd segment thickest in middle, with convex inner margin ( Fig. 579 ). Penis lobes long (nearly as long as gonostyli) and slightly divergent; each lobe with proximal part nearly parallel-sided, distal part slightly widened, without lateral pouch. From ventral view, medio-ventral ridge somewhat overlapping area laterad of it ( Fig. 580 ). Apico-lateral area forming small ear; ventro-apical plate small, not hiding base of spear from ventral view. Telopenes in form of spear-like rolls, large, widest at middle, arched caudally, somewhat bent ventrally, with groove opened dorsally-laterally ( Fig. 582 ).

Female imago (characters revealed by examination of subimago extracted from larva—Fig. 569). Black hypodermal markings on thorax as in male. Coloration of legs as in male. Coloration of abdomen with following features common with male: median longitudinal stripe, transverse stripes on posterior margins of terga, pair of especially large lateral maculae on tergum VII, smaller paired spots on other terga.

Eggs ( Figs 589–590 ). Mostly ellipsoid. Each KTC surrounded by narrow, smooth, ring-like cover. Other chorion smooth, without protuberances.

Dimension. Fore wing length (and approximate body length) 6–7.5 mm.

Variability. All 5 male imagines collected on boat 19.II.2006, have minimum black markings on thorax ( Fig. 575 ) and have red coloration on abdominal tergum IX only ( Figs 571, 573 , 475 ). Two male imagines from Pampa Hermosa (including the holotype) and from San Alejandro, as well as male subimago extracted from larva from Aguas Termales, have red and yellow coloration more or less developed on all terga VII–X ( Figs 572, 574, 576 ).

Comparison. Unusual features of Th. alboniger sp. n., not found in other Thraulodes , are wider black preapical band and narrower black apical band on hind femur and brown middle area of fore tibia. Especially large black maculae on abdominal tergum VII, besides Th. alboniger sp. n., are reported for Thraulodes venezuelana Ulmer 1943 ; the new species differs from Th. venezuelana by other features of coloration and by longer penes with longer and arched spears.

Figures

FIGURES 543–562. Thraulodes alboniger sp. n. 543, larva with ocher cuticular coloration and blackish hypodermal markings on thorax, legs and abdomen, 544–557, larval exuviae at the same magnification; 551–557, tergalii I–VII; 558, fore tibia; 559, its inner-apical margin in anterior view; 560, anterior side of fore femur; 561, hind tibia with focus on outer-posterior row of stout setae; 562, the same with focus on outer-anterior and inner-anterior rows of stout setae (544–562, holotype).

FIGURES 563–568. Thraulodes alboniger sp. n. 563, labrum; 564–565 and 566–567, male imaginal genitalia of two different specimens; 568, fragment of imaginal caudalius (563, 566–568, holotype).Abbreviations: anter.r., anterior transverse setal row; poster.r., posterior transverse setal row; other arrow show six sensilla separating five denticles.

FIGURES 569–577. Thraulodes alboniger sp. n. 569, female subimago extracted from larva; 570, apex of fore wing; 571–573, abdominal terga of three different male imagines; 574–575, two male imagines in lateral view; 576, head and thorax of male imago in dorsal view; 577, right half of subimaginal exuviae of mesonotum (570, 572, 577, holotype).

FIGURES 578–588. Thraulodes alboniger sp. n. 578, hind wing; 579, genitalia of male imago in ventral view; 580, dorsal margin of styliger and penis of another specimen; 581, subimaginal exuviae of genitalia; 582, penis in lateral view; 583, posterior margin of IX sternum of female larva; 584, the same of male larva with protogonostyli and protopenis; 585–588, tergalii I, III, VI and VII (578, 580–581, 584–588, holotype).

FIGURES 589–590. Thraulodes alboniger sp. n., 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 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).