Simothraulopsis dominguezi, 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 : 51-58

publication ID	https://doi.org/ 10.5281/zenodo.828100
publication LSID	lsid:zoobank.org:pub:5E5CC15A-009D-4E12-9342-315058D35E98
DOI	https://doi.org/10.5281/zenodo.6023588
persistent identifier	https://treatment.plazi.org/id/03CA6B06-FFB7-6C35-FF0C-FBF8EC56FE02
treatment provided by	Plazi
scientific name	Simothraulopsis dominguezi
status	sp. nov.

Treatment

Simothraulopsis dominguezi sp. nov.

( Figs 34–38 View FIGURE 34 View FIGURE 35 View FIGURE 36 View FIGURE 37 View FIGURE 38 )

Diagnosis. Male imago: 1) general coloration: thorax dark brown, abdomen brown, slightly washed with black ( Figs 34 View FIGURE 34 A–C); 2) hind wing with costal projection forming an acute angle, located approximately 2/3 distance from base to apex of wing ( Fig. 35 View FIGURE 35 B, C); 3) abdominal segment IV almost completely translucent white ( Fig. 34 View FIGURE 34 A); 4) penis projection spine-like, of median size (approximately half of the total length of penis lobes) and laterally directed ( Figs 35 View FIGURE 35 D, E); 5) penis lobes fused on basal 2/3; outer margin with a submedial concavity ( Fig. 35 View FIGURE 35 E); 6) ventral region of penis lobes without a well-marked sclerotized region ( Fig. 34 View FIGURE 34 D). Mature nymph: 1) anteromedial emargination of labrum with four denticles ( Fig. 37 View FIGURE 37 A); 2) femora and tibiae with medial and submedial wellmarked grayish brown bands ( Fig. 36 View FIGURE 36 B); 3) femur III slender, about four times longer than wide ( Fig. 38 View FIGURE 38 C); 4) posterolateral projections presents on abdominal segments V–IX, VIII–IX more developed ( Fig. 36 View FIGURE 36 C); 5) gills translucent, tracheal region gray ( Fig. 36 View FIGURE 36 D).

Male imago. Length: body: 4.5–5.2 mm; forewing: 4.8–5.1 mm; hind wing: 0.6–0.8 mm.

Head. Dorsal region dark brown washed with black, with a submedial yellowish rounded mark; ventral region whitish brown, with black marks. Upper portion of compound eyes gray, lower portion black; ocelli whitish, surrounded by dark gray ( Fig. 34 View FIGURE 34 A). Scape of antenna black, pedicel gray, flagellum translucent light gray.

Thorax. Pronotum yellowish brown, with posterior margin medial stripe black. Mesonotum dark brown slightly washed with yellow; longitudinal medial suture light brown; anterolateral scutal, lateroparapsidal suture, posterior scutal protuberance and scuto-scutellar suture dark brown; scuto-scutellar and anteronotal transverse impressions and scutellum blackish brown ( Fig. 34 View FIGURE 34 A). Pleura grayish brown; membranous area whitish ( Fig. 34 View FIGURE 34 B). Sterna whitish yellow. Wings membrane hyaline ( Figs 35 View FIGURE 35 A–C). Forewing with longitudinal veins yellowish and cross veins translucent; costal arms and base of veins C and Sc black; fork of vein MP symmetric ( Fig. 35 View FIGURE 35 A). Hind wing with costal projection well developed, forming an acute angle, located approximately 2/3 distance from base to apex of wing ( Fig. 35 View FIGURE 35 B, C); longitudinal veins brown, except base of vein C to costal projection gray; cross veins translucent; costal region dark gray, lower portion of hind wing completely black. Legs. Coxae and trochanters brown, washed with gray. Leg. I: femur light brown washed with gray, distal region with a slender, darker apical band; tibia black on distal half, remainder whitish; tarsi whitish. Legs II and III: femora with basal half whitish and distal half grayish brown; tibiae dark gray; tarsi whitish.

Abdomen. Terga brown, slightly washed with black; posterior margins black. Terga II and III with anterolateral angle and slender basal bands translucent white; tergum IV almost completely translucent white, except posterior region grayish brown; tergum X brown, with margins black and submedial whitish stripe. Sterna I–IV translucent white, remainder grayish brown, except sterna V–VII with medial region whitish ( Fig. 34 View FIGURE 34 A, B). Genitalia ( Figs 34 View FIGURE 34 D; 35D, E). Styliger plate dark brown, posterolateral angle and lateral margin dark gray. Forceps segments grayish brown, segment III with basal half whitish and distal half gray. Segment II 0.06 length of segment I, 1.1 length of segment III. Penis lobes whitish, irregularly washed with gray, fused approximately on basal 2/3, inner margins subparallel, not very close; outer margins with a submedial concavity; each lobe rounded apically, with a laterally directed spine-like projection of median size (approximately half of the total length of penis lobes); ventral region of penis lobes without a well-marked sclerotized region ( Fig. 34 View FIGURE 34 D). Caudal filaments whitish, except by basal region yellowish brown and apical margin of each segment dark brown.

Female imago. Length: body: 4.9–5.5 mm; forewing: 5.2–5.6 mm; hind wing: 0.7–0.9 mm. Color pattern similar to male imago, except by coloration lighter. Sternum IX with lateral margins brown.

Mature nymph. Length: body, 3.8–4.3 mm; antenna, 2.3–2.4 mm; cerci, 4.9–5.2 mm; caudal filament, 5.5–5.7 mm. General coloration brown washed with black ( Fig 36 View FIGURE 36 ).

Head. Yellowish brown, washed with gray near ocelli. Upper portion of male compound eyes dark brown, lower portion black. Eyes of female black. Ocelli dark gray ( Figs 36 View FIGURE 36 A, B). Scape of antenna brown, pedicel and flagellum translucent white. Maximum width of labrum 1.3 times maximum width of clypeus. Labrum ( Fig. 37 View FIGURE 37 A) light yellowish brown, with a submedial rounded yellowish gray mark, located on basal region; anteromedial emargination broad, with four denticles of equal size. Mandible ( Fig. 37 View FIGURE 37 B) brown, translucent on apical region (except incisors and molar area yellowish) and near basal articulation; with a whitish, rounded mark medially located and a gray mark near basal articulation; outer margin slightly curved, with 3–5 filiform, long, thick setae medially located. Maxilla ( Fig. 37 View FIGURE 37 C) yellowish translucent, outer margin light brown. Segment II of maxillary palpi 1.2 length of segment I, 1.8 length of segment III. Hypopharynx as in figure 38D. Labium as in figure 39E.

Thorax. Terga yellowish brown, irregularly washed with dark brown; pronotum yellowish with outer margin, submedial stripe and medial region dark gray, anterior margin with 3–4 spines; pleura brown, washed with dark gray; sterna whitish yellow. Legs. General coloration whitish; coxae with dorsal region dark gray, femora with a gray transversal line, tibiae with a medial and submedial brown bands, tarsi with a brown basal band; femora I and II with subapical and medial grayish brown bands interrupted medially. Femur III slender, about four times longer than wide ( Fig. 38 View FIGURE 38 C). Leg I. ( Fig. 38 View FIGURE 38 A). Coxa and trochanter with filiform thick setae. Femur: outer margin with apical region with few long, stout setae; inner margin with short stout setae; dorsal surface with few lanceolate and spatulate setae and with a longitudinal row of robust, bifid setae near inner margin. Tibia: inner margin and dorsal surface near inner margin with pectinate setae. Tarsus: dorsal surface with few filiform thick setae. Leg II ( Fig. 38 View FIGURE 38 B). Coxa bare. Trochanter with few filiform setae. Femur: outer margin with apical region with few long, stout setae and short stout setae; inner margin with short stout setae on apical half; dorsal surface with few lanceolate and stout setae. Tibia: inner margin with few stout setae, outer margin with long, filiform setae. Tarsus with few short stout setae along inner margin and scattered filiform setae along outer margin. Leg III ( Fig. 38 View FIGURE 38 C). Coxa bare. Trochanter with few filiform, thick setae. Femur: outer margin with basal half with short stout setae, apical half with long stout setae; inner margin with short stout setae; dorsal surface with spatulate setae. Tibia: inner margin and dorsal surface near inner margin with median stout setae; outer margin with few thin filiform setae. Tarsus with few filiform setae along outer margin.

Abdomen. Terga grayish brown; terga II and III yellowish washed with gray, medial region lighter; tergum X yellowish brown, lateral and posterior margins gray. Sterna whitish. Gills translucent, tracheal region gray ( Fig. 36 View FIGURE 36 D). Posterolateral projections present on abdominal segments V–IX, VIII–IX more developed ( Fig. 36 View FIGURE 36 C). Caudal filaments whitish yellow, with basal area light brown.

Life cycle association. Reared.

Etymology. This species is named in honor of Eduardo Domínguez, for his extensive contribution to the knowledge of South America mayflies.

Comments. Due to the very restricted distribution and low abundance of S. dominguezi sp. nov., few comments can be made concerning its biology. Nymphs were found on the roots of trees in the Negro river ( Fig. 49 View FIGURE 49 ), which probably indicates a preference for large rivers.

Imagos of S. dominguezi sp. nov. have a color pattern similar to that of S. demerara and S. janae , however, details of male genitalia ( Figs 5 View FIGURE 5 D, E; 25D; 35D, E) are enough to distinguish these three taxa. In the male, the inner margins of the penis lobes are subparallel while in S. demerara and S. janae they are divergent and parallel, respectively; the outer margin of each lobe has a submedial concavity, which is absent in both S. demerara and S. janae . Nymphs of S. dominguezi sp. nov. can be separated by the posterolateral projections on abdominal segments V–IX ( Fig. 36 View FIGURE 36 C), while in S. demerara and S. janae they are presents only on abdominal segments VIII and IX ( Figs 6 View FIGURE 6 D; 26C).

This new species probably corresponds to the subimago from the Amazonas State rapids, S. Antonio Creek near S. Antonio Mission (NW of Taparaquara, 8-1-1962, E.J. Fittkau), cited by Domínguez et al. (1997, p. 146). They mentioned the possibility of a second species of the genus associated to the Guiana Shield, in the vicinity of Taparaquara, a region near the type locality of S. dominguezi sp. nov.

Material examined. Holotype: Male imago (reared), BRAZIL, Amazonas State, Santa Izabel do Rio Negro—near the mouth of Jurubaxi river , a tributary of the Negro river (N 01°23'31.3"; W 61°43'52.2"; 51m) 05/ xii/2012, Nascimento JMC, col. ( INPA) GoogleMaps . Paratypes: one male imago, one female imago and two nymphs (same data as holotype) ( CZNC) GoogleMaps ; Barcelos : one male imago, one female imago, three nymphs, Rio Negro (N 00°28'58.5"; W 64°46'23.9", 55m) 07/xii/2012, Nascimento, JMC col. ( INPA) GoogleMaps .