Thraulodes bonito, Gonçalves, Inês Corrêa, Da-Silva, Elidiomar Ribeiro & Nessimian, Jorge Luiz, 2013

Gonçalves, Inês Corrêa, Da-Silva, Elidiomar Ribeiro & Nessimian, Jorge Luiz, 2013, Thraulodes bonito sp. nov. (Ephemeroptera: Leptophlebiidae) from Rio de Janeiro State, Southeastern Brazil, Zootaxa 3669 (2), pp. 153-158 : 154-157

Thraulodes bonito sp. nov. Gonçalves, Da-Silva and Nessimian

Diagnosis. Imago: 1) Forewings with 1–3 weakly marked cross veins basal to bullae (fig. 1); 2) Femora of forelegs with an apical transversal band weakly marked (fig. 3); 3) Abdominal color pattern as in figure 6, with terga II–VI with a pair of sublateral apical dark brown spots and a pair of diffused median markings; 4) Styliger plate triangular possessing median projection short with rounded apex (fig. 5); 5) Penes short and wide with lateral pouch present, apicolateral projection rounded, penes spines long and projected internally and posteriorly (fig. 4). Nymph: 1) Tarsal claws with 11 denticles, basal 4 denticles very small (fig. 7); 2) Mandibles smoothly curved with outer margin of both outer incisive with crenulations (figs. 15–18); 3) Gills narrow, unbranched, tapering abruptly to apex (fig. 8); 4) Legs color pattern as in figs. 9–11; 5) Abdominal color pattern as in fig. 12;

Male Imago: Length: 6.3–7.2 mm body, 6.7–7.3 mm forewings, and 1.1–1.3 mm hind wings. General coloration whitish with yellowish light brown areas. Wings hyaline.

Head: Head yellowish, heavily suffused by dark brown both ventrally and dorsally. Eyes black, turbinate portion orangish; ocelli white surrounded by a black ring at base; scape and pedicels shaded by dark brown, flagella shaded with brown.

Thorax: Pronotum yellowish; mesonotum light brown, yellowish medially, mesoscutellar hump white; metasternum light brown. Meso- and metanotum with dark brown markings laterally near legs and wings insertions. Prosternum and metasternum yellowish; mesosternum yellowish bearing a median dark brown marking overlaid by 2 longitudinal light brown bands.

Legs (fig. 3): All legs whitish, femora with inner margin dark brown and a weakly marked dark brown band, both on apical third. Apical third of femora light brown.

Wings (figs. 1–2): Membrane of wings hyaline with dark brown stain at base; veins whitish. Membrane between C and Sc of forewings whitish on apical third. One to 3 cross veins basal and 11–15 distal to bullae. Hind wings with 7–11 cross veins.

Abdomen (fig. 6): Terga I–VI translucent white; tergum I with anterior margin dark brown; Terga II–VI with a pair of sublateral apical dark brown spots and a pair of diffused, poorly defined, median markings; Pair of sublateral dark brown spots on tergum II weakly marked or missing in some specimens; tergum VI with posterior margin dark brown; terga VII–X yellowish; terga VII–VIII with anterior and posterior margins dark brown. Sterna I–VI translucent white; sterna II–VII possessing a pair of apical lateral dark brown spots; sterna VII–IX yellowish. Caudal filaments whitish with wide dark brown annulations.

Genitalia (figs. 4–5): Styliger plate triangular, whitish, with posterior median projection short with rounded apex. Forceps whitish, with strong constriction near middle of segment I; several short setae on inner margin of segment I basal to constriction. Penes short and robust, with lateral pouch; apicolateral area with apex rounded; recurved fold subtly marked; spines long, projected internally and posteriorly.

Female Subimago: Length: 7.5 mm body, 8.2 mm forewings, and 1.5 mm hind wings. General coloration yellowish. Wings hyaline.

Head: Head yellowish suffused with dark brown, anterior margin of head translucent yellowish. Eyes black; ocelli white surrounded by a black ring at base; scape and pedicels shaded by dark brown, flagella shaded with brown.

Thorax: Pronotum whitish possessing a median longitudinal dark brown marking; meso- and metanotum yellowish. Mesonotum with a pair of divergent longitudinal brown lines and several scattered brown lines meso and metanotum with lateral dark brown markings near legs and wings insertions. Prosternum whitish; meso- and metasternum yellowish.

Legs: Similar to male, except color pattern not so marked.

Wings: Membrane whitish with dark brown stain at base; veins whitish. One cross vein basal and 15 veins distal to bullae.

Abdomen: Segments yellowish, filled with eggs; terga suffused with brown, tergum I heavily suffused with dark brown. Sterna II–VII possessing a pair of apical lateral dark brown spots. Caudal filaments lost.

Nymph: Length: 6.7–7.5 mm body, and caudal filaments>8.0 mm (broken). General coloration light brown. Head (figs. 13–18): Head light brown; area immediately in front of median ocelli, epicranial stem, epicranial arms and posterior margin of head yellowish. Eyes black; ocelli black. Scape and pedicels light brown, flagella translucent yellow. Labrum light brown, wider than clypeus, width about 3 times length, angles of lateral margins rounded and anterior margin with very broad, shallow emargination with 5 subtle crenulations; presence of apical and subapical rows of whitish setae; dorsal surface covered by short and scattered whitish setae. Mandibles light brown, whitish on apical third; presence of row of whitish setae on outer margin extending to level of outer incisor; setae long on distal half and short on basal half; incisors with all margins serrate; molars with serrate ridges; prosthecae well developed. Right mandible outer incisor with 3 apical denticles; inner incisor with 2 denticles; setae near molars light brown. Left mandible with 3 denticles on inner and outer incisors. Maxilla yellowish, flattened and rectangular; apical margin brown; palpi yellowish. Hypopharynx whitish with light brown setae. Labium whitish, densely covered by long yellowish setae on glossa and apical third of paraglossa; first segment of palpi with both margins bearing long yellowish setae; second and third segments with fewer setae, concentrated apically.

Thorax: Pronotum, mesonotum and metanotum light brown. Base of the wing-pads with a dark brown stain. Thoracic sterna yellowish.

Legs (figs. 7 and 9–11): Legs yellowish. Coxa of fore and mid legs light brown, hind coxa yellowish with wide light brown margins; all coxae with a row of long simple setae on outer margin. Femora shaded with light brown in some areas; dorsal surface of femora bearing scattered short bristles, mid and hind femora with row of spines on inner margin; outer margin of femora with row of long simple setae and few clavate setae and spines. Foretibiae and tarsi of all legs possessing a wide median light brown band; Outer margin of tibiae bordered by long simple setae; hind tibiae also with few scattered clavate setae; inner margin of tibiae bearing small spines. Tarsi with very few long simple setae. Tarsal claws with 11 denticles, the basal 4 very small, subequal in size.

Abdomen (figs. 8 and 12): Terga light brown. Anterior margin of tergum I heavily suffused with dark brown; abdominal color pattern of both sexes of mature nymphs very similar to male imagos, with terga II–VII possessing a pair of sublateral apical dark brown spots and a diffuse, poorly defined, median marking. Sterna yellowish. Caudal filaments yellowish with dark brown annulations. Gills narrow, tapering abruptly toward apex, main tracheae unbranched.

Variations: Some nymphs with a pair of apical sublateral yellowish spots on pronotum. One nymph with fainted color pattern on abdomen, without median markings; other specimens with median markings only on terga II–V or II–VI.

Biology. Nymphs were found crawling under rocks in moderate current speed or on marginal vegetation in large rivers. The new species was found on sites ranging from 300–1.000 meters above sea level, in several river sizes (1st–6th order streams).

Life cycle associations. Nymphs and winged stages were associated based on one male nymph reared to subimago. Female were associated with males occurring in the same swarm.

Etymology. The term “ bonito ” is in allusion to the Bonito River basin, were the new species was found and the type-locality of the holotype.

Type material. Brazil, Rio de Janeiro State: Holotype: Nova Friburgo, Lumiar, Rio Bonito de Lumiar, Toca da Onça, Rio Bonito , 22o 24' 05.6" S / 42o 19' 17.8" W, 608 m, 05.III.2009, Gonçalves, I.C. leg., 1 male imago (DZRJ2329); Paratypes: same locality, 06.III.2009, Gonçalves, I.C. leg., 1 male imago (DZRJ2330); Nova Friburgo, Lumiar, Rio Bonito de Lumiar, 2nd order tributary of Rio Bonito , 22o 24' 27.7" S / 42o 25' 05.1" W, 792 m, 29.X.2009, Gonçalves, I.C. leg., 1 male subimago and 1 nymphal exuvia (reared) (DZRJ2331); Nova Friburgo, Lumiar, Rio Bonito de Lumiar, Rio Bonito in 5th order, 22o 24' 38.5" S / 42o 20' 40.7" W, 656 m, 06.III.2009, Gonçalves, I.C. leg., 1 male subimago (DZRJ2332); Nova Friburgo, Lumiar, Toca da Onça, Rio Bonito in 5th order, 22o 24' 05.6" S / 42o 19' 17.8" W, 608 m, 05.III.2009, Gonçalves, I.C. leg., 2 male imagos and 1 female subimago (DZRJ2333); same data, 1 male subimago (DZRJ2334); Nova Friburgo, Lumiar, Toca da Onça, 3th order tributary of Rio Bonito , 22o 24' 38.2" S / 42o 20' 38.6" W, 669 m, 30.X.2009, Gonçalves, I.C. leg., 1 nymph (DRZJ2335); Nova Friburgo, Lumiar, Toca da Onça, Córrego dos Patos in 2th order, 22o 24' 45.5" S / 42o 19' 10.6" W, 670 m, 08.II.2009, Oliveira, A.L.H. leg., 2 nymphs (DZRJ2336); Nova Friburgo, Lumiar, Toca da Onça, Córrego das Paineiras in 3rd order, 22o 23' 27.2" S / 42o 20' 03.6" W, 694 m, 24.V.2008, Toste, T.M., Cruz, T. and Padua, A. leg., 1 nymph (DZRJ2337); same data, 1 nymph (DZRJ2338); Nova Friburgo, Lumiar, Córrego do Poço Feio in 2nd order, 22o 21' 04,7" S / 42o 20' 02.7" W, 594 m, 13.XI.2008, Gonçalves, I.C. leg., 1 nymph (DZRJ2339); same locality, same date, Alecrim, V.P. leg., 1 nymph (DZRJ2340); Macaé, Sana, Rio Sana in 3rd order, 22o 14' 42.3"S / 42o 09' 03.2"W, 567m, 18.II.2009, Gonçalves, I.C. leg., 1 nymph (DZRJ2341); Macaé, Sana, Córrego da Ilha in 2nd order, 22o 20' 41.8"S / 42o 11' 03.7"W, 381 m, 19.II.2009, Gonçalves, I.C. leg., 1 nymph (DZRJ2342); same data, 2 nymphs (DZRJ2343); Macaé, Frade, 2nd order tributary of Rio São Pedro, 22o 13' 47.6" S / 42o 08' 04.7" W, 470 m, 20.III.2009, Gonçalves, I.C. leg., 1 nymph (DZRJ2344).