Simothraulopsis eurybasis, Do, Jeane M. C., Salles, Frederico F. & Hamada, Neusa, 2017

Do, Jeane M. C., Salles, Frederico F. & Hamada, Neusa, 2017, Systematics of Simothraulopsis Demoulin, 1966 (Ephemeroptera: Leptophlebiidae), Zootaxa 4285 (1), pp. 1-81 : 58-63

Simothraulopsis eurybasis sp. nov.

( Figs 39–43 )

Diagnosis. Male imago: 1) general coloration: thorax orangish brown, abdomen blackish brown ( Figs 39 A–C); 2) hind wing with costal projection almost forming a right angle, located approximately 1/2 distance from base to apex of wing ( Figs 40 B, C); 3) abdominal segment IV almost completely white ( Figs 39 A); 4) penis projection spine-like, short and directed to the midline of the body ( Fig. 40 D, E); 5) penis lobes widely separated, almost underneath by the forceps from ventral view; 6) penis lobes fused on basal 1/4 ( Fig. 40 D); 7) ventral region of penis lobes without a well-marked sclerotized region ( Fig. 39 D). Mature nymph: 1) inner margin of fore tibia with a row of pectinate setae ( Fig. 43 A); 2) femur III slender, about four times longer than wide ( Fig. 43 C); 3) posterolateral projections presents on abdominal segments VIII and IX ( Fig. 41 C); 4) gills hyaline, tracheal region gray ( Fig. 41 D).

Male imago. Length: body: 5.2–5.4 mm; forewing: 6.1–6.3 mm; hind wing: 1.2–1.4 mm.

Head. Dorsal region orangish brown washed with black, with a submedial orangish rounded mark; ventral region whitish, with black marks. Upper portion of compound eyes grayish brown, lower portion black; ocelli whitish, surrounded by black ( Figs 39 A, B). Scape and pedicel of antenna translucent yellow, flagellum translucent white.

Thorax. Pronotum orangish brown, with both lateral and posterior margins darker; submedial and mediolongitudinal stripes black. Mesonotum orangish brown; longitudinal medial suture light brown; anterolateral scutal and lateroparapsidal sutures black; scuto-scutellar impression and scutellum black. Pleura orangish brown; membranous area dark gray. Sterna yellowish brown. Wings membrane hyaline ( Figs 40 A–C). Forewing with longitudinal and cross veins light yellow translucent; costal arms and base of veins C and Sc black; fork of vein MP symmetric ( Fig. 40 A). Hind wing with costal projection well developed, almost forming a right angle, located approximately 1/2 distance from base to apex of wing; longitudinal veins brown, except base of vein C and Sc grayish brown; cross veins translucent; costal region dark gray, almost the entire lower portion of hind wing blackish brown ( Figs 40 B, C). Legs. Coxae and trochanters whitish yellow, washed with gray. Leg. I: femur orangish brown with a whitish apical band; tibia with a dark gray basal band, remainder whitish; tarsi whitish. Legs II and III: femora orangish brown with basal and apical bands whitish; tibiae gray with subapical region whitish; tarsi whitish with distal region of tarsomeres light brown.

Abdomen. Terga I–III blackish brown, except posterior margin black and anterolateral region of terga II and III translucent white; tergum IV almost completely white, except medial region washed with grayish brown and posterior margin black; terga V–IX black, except anterior region of terga V and VI whitish and anterior region of tergum VII yellowish. Tergum X yellowish brown, with margins dark brown and both submedial and medial stripes brown ( Figs 39 A, B). Sterna I–IV translucent white, lateral region of sterna V and VI with a brown mark; other sterna brown with lateral region blackish brown. Genitalia ( Figs 39 D; 40D, E). Styliger plate yellowish brown, posterolateral angle and lateral margin blackish brown. Forceps segment I blackish brown, segments II and III whitish, except apical region of segment II brown. Segment II 0.1 length of segment I, 1.2 length of segment III. Penis lobes yellowish, lobes with a small black mark located near outer margin; penis lobes widely separated, almost underneath by the forceps from ventral view and fused on basal 1/4; inner margins divergent; each lobe rounded apically, with a short (less than the half of total length of penis lobes), spine-like projection, directed to the midline of the body; ventral region of penis lobes without a well-marked sclerotized region ( Fig. 39 D). Caudal filaments broken and lost.

Female subimago. Length: body: 5.4–5.7 mm; forewing: 6.3–6.5 mm; hind wing: 1.3–1.5 mm. Color pattern similar to male imago, except by coloration more yellowish ( Fig. 39 C). Sternum IX with lateral margins light brown.

Mature nymph. Length: body, 4.4–4.9 mm; antenna, 2.3–2.4 mm; cerci, 4.5–4.9 mm; caudal filament, 5.1–5.3 mm. General coloration brown washed with black ( Figs 41 ).

Head. Brown, with blackish gray marks. Upper portion of male compound eyes reddish brown, lower portion black. Eyes of female black. Ocelli dark gray. Scape of antenna dark brown, pedicel and flagellum translucent white. Maximum width of labrum 1.2 times maximum width of clypeus. Labrum ( Fig. 42 A) yellowish brown washed with gray, with a submedial rounded dark gray mark; anteromedial emargination broad, with four denticles of equal size. Mandible ( Fig. 42 B) brown, translucent on apical region (except incisors and molar area orangish yellow) and near basal articulation; with a translucent yellow, rounded mark medially located and scattered gray marks; outer margin slightly curved, with 2–4 filiform, long, thick setae medially located. Maxilla ( Fig. 42 C) yellowish translucent, outer margin grayish brown, region near basal articulation gray. Segment II of maxillary palpi 1.3 length of segment I, 2.0 length of segment III. Hypopharynx as in figure 42D. Labium as in figure 42E.

Thorax. Terga brown, irregularly washed with blackish gray, central region yellowish; anterior margin of pronotum with 1–2 spines; pleura brown, irregularly washed with gray; sterna whitish. Legs. General coloration whitish; coxae with dorsal region dark brown, femora with a light gray transverse line. Femora I and II almost completely whitish, except a mediolongitudinal light brown band and subapical dark gray band; femur III almost completely brown, without well-marked bands; with a subapical dark gray brown mark and apical whitish mark. Tibiae and tarsi whitish; tibiae with basal and submedial brown bands; tarsi with a basal brown band. Femur III slender, about four times longer than wide ( Fig. 43 C). Leg I. ( Fig. 43 A). Coxa with few filiform setae located near dorsal margin. Trochanter with few lanceolate setae. Femur: outer margin with apical region with long, stout setae; apical half of inner margin with short stout setae; dorsal surface with: few spatulate setae, spatulate setae with bifid apex and robust, short, bifid setae. Tibia: inner margin with pectinate setae and with a longitudinal dorsal row of filiform, thick setae near inner margin. Tarsus with filiform thick setae along inner margin. Leg II ( Fig. 43 B). Coxa bare. Trochanter with few filiform setae. Femur: apical region of outer margin with long stout setae; inner margin with apical half with short stout setae; dorsal surface with spatulate setae with bifid apex and with robust, short, bifid setae. Tibia: inner margin with few stout setae; dorsal surface near inner margin with spatulate setae with bifid apex. Tarsus with few stout setae along inner margin. Leg III ( Fig. 43 C). Coxa and trochanter bare. Femur: outer margin with apical half with long, stout setae; inner margin with apical half with short stout setae; dorsal surface with simple spatulate setae and spatulate setae with bifid apex. Tibia: inner margin with few stout setae and with spatulate setae with bifid apex near inner margin; outer margin with a row of teardrop shaped setae. Tarsus with few stout setae along to outer margin.

Abdomen. Terga blackish brown with posterior margins black and lateral regions yellowish brown, except tergum II almost completely yellowish brown. Sterna yellowish, lateral region washed with gray. Gill translucent, tracheal region gray ( Fig. 41 D). Posterolateral projections present on abdominal segments VIII and IX ( Fig. 41 C). Caudal filaments yellowish brown, with basal area light dark brown.

Life cycle association. Male subimago extracted from nymph and compared with the imagos.

Etymology. From the Greek word eurys, wide; and basis, base. In reference to the wide distance between the apices of penis lobes.

Comments. Simothraulopsis eurybasis sp. nov. has a distribution restricted to the north of the Espírito Santo state ( Fig. 49 ). Imagos were collected mostly by light traps from large rivers. The two collected nymphs were found in submerged stones in a rock bottomed stream.

Male imagos of S. eurybasis sp. nov. and S. diamantinensis have similar penis lobes, with short, spine-like, penis projection ( Figs 20 D, E; 40D, E). The new species, however, can be distinguished from other species of Simothraulopsis by the distance between the penis lobes (they are so widely separated, that are almost covered by the forceps in ventral view). Besides that, coloration of hind wings and general coloration of the body may also prove helpful with identification: in S. eurybasis sp. nov. the pigmented area below vein R is wider and the abdominal coloration is darker ( Figs 19 A, B; 20C; 39A, B; 40C). Nymphs of these two species can be separated from each other by the general coloration: in S. eurybasis sp. nov. the thorax is more marked and the abdomen is darker ( Figs 21 A, E; 41A, E).

Material examined. Holotype: Male imago (light trap), BRAZIL, Espírito Santo State, Sooretama, São José river (S 19°07'33.1"; W 40°14'26.1"; 24m) 19/v/2011, Salles FF & Nascimento JMC, cols. ( INPA) . Paratypes: five male imagos, six female imagos and two nymphs (same data as holotype) (two male imagos, two female imagos, one nymph at IBN; two male imagos, two female imagos and one nymph at CZNC; two male imagos, two female imagos and one nymph at DZRJ) ; two male imagos, Nova Venécia, Patrimônio do Bis (S 18°33'27.5"; W 40°20'6.5"; 188m) 25-26/vii/2012, Salles FF & Angeli K cols ( INPA) ; one male imago, Nova Venécia, Santa Rita do Pipi Nuck (S 18°39'51.4''; W 40°30'44.9''; 80m) 18-19/iv/2012, Salles FF & Angeli K cols ( CZNC) .

Figures

FIGURE 19. Simothraulopsis diamantinensis, male imago. A) habitus, dorsal view; B) habitus, lateral view; C) head and thorax, detail; D) genitalia, ventral view.

FIGURE 20. Simothraulopsis diamantinensis, male imago. A) forewing; B) hind wing; C) enlarged hind wing; D) genitalia, ventral view; E) penis lobes, detail.

FIGURE 21. Simothraulopsis diamantinensis, nymph. A) male, dorsal view; B) male, lateral view; C) female, dorsal view; D) gill IV; E) abdomen, ventral view.

FIGURE 39. Simothraulopsis eurybasis sp. nov., imago. A) male, dorsal view; B) male, lateral view; C) female subimago, dorsal view; D) male genitalia, ventral view.

FIGURE 40. Simothraulopsis eurybasis sp. nov., male imago. A) forewing; B) hind wind; C) enlarged hind wing; D) genitalia, ventral view; E) penis lobes, detail.

FIGURE 41. Simothraulopsis eurybasis sp. nov., nymph. A) dorsal view; B) lateral view; C) abdomen, ventral view; D) gill IV.

FIGURE 42. Simothraulopsis eurybasis sp. nov., nymph, mouthparts. A) labrum, dorsal view; B) right mandible; C) maxilla; D) hypopharynx; E) labium.

FIGURE 43. Simothraulopsis eurybasis sp. nov., nymph. A) foreleg; B) middle leg; C) hind leg.

FIGURE 49. Map of South America showing the distribution of Simothraulopsis species. Red color represents previous records. Other colors represent new records.