Traverella insolita, Do Nascimento, Jeane M. C. & Salles, Frederico F., 2013

Do Nascimento, Jeane M. C. & Salles, Frederico F., 2013, New species of Hermanella complex (Ephemeroptera: Leptophlebiidae) from Brazilian Atlantic Forest, Zootaxa 3718 (1), pp. 1-27 : 19-26

Traverella insolita , sp. nov.

( Figs. 13–17 )

Diagnosis. Male imago: (1) subgenital plate strongly projected posteriorly and fused medially, forming three broad and short projections ( Fig. 14 D); (2) penis lobe divided on distal ¾; (3) penis lobe laterally sinuous and apically rounded, with a ventral, long, narrow spine curved toward the midline of the body ( Fig. 14 E); (4) abdomen with contrasting color pattern (segments II–VI translucent, segments I, and VIII–X brown and reddish brown, respectively, Figs. 13 A, B); (5) vein ICu1 of forewings attached to vein CuA ( Fig. 14 A). Nymph: (1) clypeus without a anteromedial projection ( Figs. 15 A, B); (2) galea-lacinia with a prominent tusk on inner apical angle (nearly half of the apical width of galea-lacinia, Fig. 16 C); (3) mandible without dorsal row of setae, with 3–5 thick and short setae ( Fig. 16 B); (4) gills gray, present on segments I–VII.

Male imago. Length: body, 6.5–7.0 mm; forewing, 5.8–6.4 mm; hind wing, 1.0– 1.3 mm.

Head. Dorsal region yellowish brown with dark brown marks; ventral region whitish. Upper portion of compound eye orangish brown, lower portion black; ocelli whitish, surrounded by dark brown. Antenna. Scape and pedicel brown, flagellum light brown translucent.

Thorax. Pronotum yellowish brown washed with dark gray, with medial strip, submedial mark and lateral margin black; mesonotum brown, except for mediolongitudinal, medioparapsidal and lateroparapsidal sutures yellowish, scuto-scutellar impression whitish; metanotum yellowish-brown with brown areas; pleurae yellowishbrown with sclerites dark brown; sterna yellowish brown, prosternal carina narrow. Wings ( Figs.13 A, B and 14A– C). Membrane hyaline, brown at base. Forewing with longitudinal veins yellowish and cross veins translucent, vein ICu1 of fore wing attached to vein CuA; hind wing with longitudinal and cross veins translucent, vein C brown in basal third. Legs. Legs whitish; coxae yellowish brown washed with black; femora with an apical dark reddish brown band. Leg I: femur with a median gray mark; tibia with a basal slender brown band and an apical grayish brown band; tarsomeres with an apical light gray band.

Abdomen. Tergum I brown washed with black, terga II–VI translucent, posterior margin of terga II–V with a dark brown transversal band interrupted laterally, terga VI–IX with posterior margin entirely dark brown; terga VII–X reddish brown washed with gray, tergum VII with an anteromedial triangular mark. Sterna I–VII translucent; VII–IX reddish brown, medial region lighter. Genitalia ( Figs. 14 D, E). Subgenital plate brown, posteriorly projected, forming a broad and short projection of rounded apex that ventrally obstruct the view of penis. Forceps. Forceps whitish, segment II 0.2 length of segment I, 1.2 length of segment III. Penis divided on distal ¾, each lobe laterally sinuous and apically rounded, with a ventral, long and narrow spine curved toward the midline of the body ( Fig. 14 E); penis lobe whitish yellow; spine orangish brown. Caudal filaments whitish, apical region of each segment with a grayish brown band.

Female Imago. Unknown.

Mature Nymph. Length: body, 6.0– 6.8 mm; antenna, 2.7–3.0 mm; cerci, 6.0– 6.4 mm; terminal filament, 7.0– 7.5 mm. General coloration yellowish brown, female darker ( Figs. 15 A, B).

Head. Yellowish brown, washed with gray. Upper portion of male compound eye dark brown, lower portion black. Eye of female black. Antenna whitish yellow. Clypeus without a anteromedial projection ( Figs. 15 A, B), lateral margin strongly concave, maximum width of labrum 1.5 times maximum width of clypeus. Mouthparts ( Figs. 16 A–E). Labrum ( Fig. 16 A) brown, U-shaped anteromedial emargination; with dorsal proximal row of 14– 16 long setae interrupted medially; numerous ventral setae directed obliquely to sagittal plane. Mandible ( Fig. 16 B) grayish brown, translucent near to incisors, with one pair of median translucent rounded spots; outer margin strongly curved, forming a square angle; without dorsal row of setae and with 3–5 thick and short setae near to basal articulation. Maxilla ( Fig. 16 C). Galea-lacinia with a prominent tusk on inner apical angle (nearly half of the apical width of galea-lacinia). Hypopharynx as in figure 16D. Labium as in figure 16E.

Thorax. Terga yellowish brown, irregularly washed with grayish brown; pronotum with a submedial stripe and lateral margin dark gray, apico-lateral angle with 3–5 thick setae; pleura yellowish, washed with gray; sterna whitish yellow. Legs. Whitish yellow; coxae washed with gray. Leg I ( Fig. 17 A). Femur with a subapical band and dorsal gray mark. Legs II and III ( Figs. 17 B, C) slightly washed with light brown; femora with a gray band. Femora with long setae and spine-like setae along external margin; dorsal surface covered with long spine-like setae, absent in femur I. Tibia I ( Fig. 17 A) with few short spine-like setae along inner margin and long spine-like setae in dorsal surface, long and thin setae along outer margin; tibia II ( Fig. 17 B) with long and thin setae along outer margin and row of spine-like setae in dorsal surface; tibia III ( Fig. 17 C) with spine-like setae and long setae in external margin and long spine-like setae in dorsal surface and inner and apical margins. Tarsal claws strongly hooked ( Fig. 17 D) without subapical denticle, 3–5 median denticles subequal in size, without accessory denticles.

Abdomen. Terga yellowish brown, segments VII–X darker; segment I washed with gray. Sterna whitish yellow. Gills gray ( Fig. 17 E), present on segments I–VII, bearing numerous and slender filaments in almost its entire length. Caudal filaments yellowish brown.

Life cycle association. Nymphs and male imagos are tentatively associated by sharing the same color pattern of legs and by basal portion of the dark wing pad of the nymph, which corresponds to the colored basal portion of the adult's wing. The two associated stages were also collected at the same place.

Etymology. From the Latin word insolitus, unusual, uncommon; with reference to the fact that the new species is the first of the genus in which the clypeal projection is absent.

Material examined. Holotype: Male imago (light trap), Brazil, Espírito Santo State, Pedro Canário, Rio Itaúnas (S 18° 12' 10.8", W 40° 06' 25.2"), 35m, 29/iii/2011, JMC Nascimento, EA Raimundi, FC Massariol, KB Del-Carro, PVA Brito cols. (INPA). Paratypes: eight male imagos, same date of holotype (two at CZNC; two at INPA; two at DZRJ; two at IBN); four male imagos (light trap) and 13 nymphs, Brazil, Espírito Santo, Sooretama, Rio São José (S 19°07'33.1'', W 40°14'26.1''), 24m, 19/v/2011, JA Rúdio, JMC Nascimento, P Barcelos-Silva cols. (four nymphs, one male at CZNC; three nymphs, one male at INPA; three nymphs, one male at IML; three nymphs, one male at DZRJ).

Comments. The new species is similar to Traverella (Traverella) bradleyi (Needham & Murphy, 1924) due to the color pattern and by the shape of the spine on penis. However, it can be distinguished from this species by the lateral margin of penis, which is sinuous in the new species and straight in T.(T.) bradleyi , and by projections of the male styliger plate – broad, short and medially united in the Traverella insolita , sp. nov. but long and narrow in T. (T.) bradleyi (Domínguez et al. 2006). With respect to the color pattern, same to is also observed in other species of the genus or even in other genera of the Hermanella complex, such as Traverella longifrons Lugo-Ortiz & McCafferty, 1996 , Hermanella mazama (Nascimento, Mariano & Salles 2012) (in Lima et al. 2012), Hylister chimaera Kluge, 2007 and Hylister obliquus sp. nov. (see above).

Among the diagnostic characteristics of Traverella insolita , sp. nov., the styliger plate strongly projected posteriorly, hindering the vision of penes is very unusual. The same feature is observed in Thraulodes criptodrylus (Nieto & Domínguez, 2001) and recently, Gonçalves et al. (2012) also stated this character for Poranga nessimiani (Gonçalves & Da-Siva). However it is probably a convergence since these genera are not closely related. Domínguez (1995) established a new subgenus Traverella (Zonda) , and used the following characters to distinguish the imago of the subgenus Traverella (Traverella) : vein ICu1 of fore wing attached to vein CuA (as seen in new species) and male styliger plate with long, narrow paired projections. However, the species herein described presents the male styliger plate with broad and short projections. With respect to the immature stage, all characters proposed for the subgenus Traverella , but one, were observed in the nymphs analyzed (tusk present at inner anterior angle of maxillae, segment II of maxillary palpi long, segment III of labial palpi not elongated and gills present on abdominal segment seven). The single exception lies on the presence of a row of spine-like setae on the fore tibia, a characteristic attributed to the subgenus Zonda .

Moreover, the nymph of Traverella insolita , sp. nov. is the first of the genus in which the frontoclypeal projection is absent and the first with a prominent tusk on galea-lacinia, characteristics that must be included in the generic diagnoses proposed by Allen (1973) and Domínguez et al. (2006).

Despite having many congruent characters with representatives of Traverella (Traverella) , the new species has a number of derived characters, as well as other intermediaries among the two subgenera proposed for the group, not fitting securely in any of them. Based on this scenario, we hypothesize that either the concepts used in subgeneric diagnoses must be modified or a new subgenus should be erected to accommodate the new species. In the absence of a phylogenetic analysis, we prefer to keep the new species not attributed to any subgenera.

In order to incorporate the male imago of Traverella insolita , sp. nov. the following modification is proposed to the key of Domínguez et al. (2006, p. 514).

1. Vein ICu1 of fore wings attached to vein CuA (Domínguez et al. 2006, Fig. 193D).................................. 2

- Vein ICu1 of fore wings free basally (Domínguez et al. 2006, Fig. 193A)............... Traverella (Zonda) calingastensis

2(1). Styliger plate strongly projected posteriorly, hindering the vision of penes, with broad and short projection ( Fig. 14 D)...................................................................................... Traverella insolita sp. nov.

- Styliger plate not strongly projected posteriorly, with narrow and long projection............. Traverella (Traverella) … 3

3(2). Wing membranes almost hyaline............................................... Traverella montium Ulmer, 1943

- Wing membranes with some coloration pattern.............................................................. 4

4(3). Wing membranes translucent brown; costal area and cross veins blackish brown................... Traverella valdemari

- Wing membranes hyaline with prominent brown areas at bases; cross veins translucent............... Traverella bradleyi

Figures

FIGURE 13. Traverella insolita, sp. nov., male imago. A) lateral view; B) dorsal view.

FIGURE 14. Traverella insolita, sp. nov., male imago. A) forewing; B) hind wing; C) enlarged hind wing; D) male genitalia, ventral view; E) detail of penes, ventral view.

FIGURE 15. Traverella insolita, sp. nov., habitus of nymph A) male; B) female.

FIGURE 16. Traverella insolita, sp. nov., nymphal mouthparts. A) labrum: left: dorsal view, right: ventral view; B) mandible; C) maxilla; D) hypopharynx; E) labium: right: ventral view, left: dorsal view.

FIGURE 17. Traverella insolita, sp. nov., nymph. A) fore leg; B) middle leg; C) hind leg; D) tarsal claw; E) gill IV.