Tricorythodes biluhue, Emmerich & Molineri, 2020

Emmerich, Daniel & Molineri, Carlos, 2020, A new species of Tricorythodes Ulmer (Ephemeroptera: Leptohyphidae) from Uruguay, Zootaxa 4885 (1), pp. 125-132 : 126-132

Tricorythodes biluhue sp. nov.

( Figures 1–28 )

Type material. Holotype ( MUR) female mature nymph from Uruguay, Tacuarembó, A° Tranqueras , S 31° 47’ 29” – W 55° 58’ 51”, 22/II/2008, Emmerich & Molineri cols . Paratypes ( IBN): 10 nymphs, same data as holotype. One nymph, Uruguay, Salto, Arroyo (abbreviation = A°) Itapebí , finca Iribarne , S 31º 22’ 3.4” – W 57º 32’ 24.5”, 102 m, 17/II/2008, Emmerich & Molineri cols. 16 nymphs, Uruguay, Artigas, Aº de los Chanchos , S 30º 34’ 48.3” – W 56º 37’ 10.8”, 130 m, 18/II/2008, Emmerich & Molineri cols. Three nymphs, Uruguay, Artigas, Finca Mataojo Grande , Aº Mataojo Grande , 274 m, S 31º 17’ 29.7” – W 56º 13’ 10”, 18/II/2008, Emmerich & Molineri cols. Two nymphs, Uruguay, Rivera, Tranqueras , río Tacuarembó , 147 m, S 31º 10’ 40” – W 55º 45’ 44”, 19/II/2008, Emmerich & Molineri cols. Two nymphs, Uruguay, Rivera, Santa Ernestina , A° sin nombre , 146 m, S 31º 32’ 23.8” – W 55º 33’ 42”, 19/II/2008, Emmerich & Molineri cols. Two nymphs, Uruguay, Rivera, Mina de Corrales , Aº Corrales , 140 m, S 31º 34’ 34” – W 55º 27’ 58”, 19/II/2008, Emmerich & Molineri cols. Three nymphs, Uruguay, Rivera, Aº Zapucay , 140 m, S 31º 47’ 01” – W 55º 20’ 02”, 19/II/2008, Emmerich & Molineri cols. Two nymphs, Uruguay, Tacuarembó, A° Carpintería , 121 m, S 31º 48’ 28” – W 55º 13’ 09”, 20/II/2008, Emmerich & Molineri cols. Six nymphs, Uruguay, Cerro Largo, Aº Tacuarí , 92 m, S 32º 31’ 51” – W 54º 07’ 48”, 20/II/2008, Emmerich & Molineri cols. One nymph, Uruguay, Durazno, Sarandí del Yí , río Yí , 132 m, S 33° 20’ 41” – W 55° 37’ 07”, 22/II/2008, Emmerich & Molineri cols. Two nymphs, Uruguay, Tacuarembó, Valle Edén , A° Tambores , S 31° 48’ 48” – W 56° 10’ 24”, 160 m, 23/ II/2008, Emmerich & Molineri cols. Six nymphs, Uruguay, Paysandú, A° Soto , 43m, S 32° 03’ 10” – W57° 40’ 23”, 23/II/2008, Emmerich & Molineri cols. One nymph, Uruguay, Paysandú, A° Guayabos Grande , 83 m, S 32° 22’ 45” – W 57° 20’ 11”, 1/III/08, Emmerich & Pérez, cols. 15 nymphs, Uruguay, Río Negro , A° Don Esteban , 34 m, S 32° 50’ 07” – W 57° 30’ 59”, 2/III/2008, Emmerich & Pérez cols. Seven nymphs, Uruguay, Flores, Camino vecinal , A° sin nombre , 115 m, S 33° 42’ 52” – W 56° 39’ 40”, 2/III/2008, Emmerich & Pérez cols. Three nymphs, Uruguay, Lavalleja, Minas, Cañada Solís , 123 m, S 34° 24’ 08” – W 55° 21’ 11”, 3/III/2008, Emmerich & Pérez cols. Six male imagoes, one female imago, Uruguay, Maldonado, A° El Rodeo , 75 m, S 34° 40’ 20” – W 55° 14’ 15”, 7–8/XI/2008, Emmerich col. Two nymphs, Uruguay, Paysandú, A° Sacra , 10 m, S 32° 21’ 02” – W 58° 03’ 04”, 7/III/2008, Emmerich & Pérez cols. Two nymphs, Uruguay, San José, Aº Pavón , 86 m, S 34° 18’ 53.2” – W 56º 52’ 24.7”, 6/XI/2008, Emmerich col. Two nymphs , Uruguay, Rivera, Cañada sin nombre , 289 m, S 31º 05’ 36.7” – W 55º 57’ 57.9”, 11/ XI/2008, Emmerich col. Three nymphs, Uruguay, Tacuarembó, A° Potrero , 157 m, S 31º 54’ 13.9” – W 56º 46’ 34.9”, 26/III/2010, Emmerich & Molineri cols. One nymph. Uruguay, Río Negro , ”El Chicharrón” , A° Grande , S 32º 31’ 45” – W 57º 08’ 11.9”, 9/8/07. E. Morelli & A. Verdi cols .

Diagnosis. The nymphs of Tricorythodes biluhue sp. nov. can be distinguished from all other species of the genus by the following combination of characters: 1) maxillary palp 2 to 3–segmented ( Figs. 6–7 ); 2) hypopharynx with spine on inner margin of superlinguae ( Fig. 9 ); 3) pronotum with pointed anterolateral projection and small blunt tubercle medially; 4) legs relatively long and slender, covered with long setae ( Figs. 11, 13 and 14 ); 5) fore tarsal claws with 10–13 marginal denticles and with 0–1 + 1 submarginal denticles ( Fig. 12 ); 6) abdominal segments with lateral flanges on III–VI and small posterolateral spines on VI–IX ( Fig. 17 ); 7) operculate gills subtriangular, shaded widely except on paler area close to insertion ( Fig. 18 ); 8) gills III–V with relatively wide ventralmost lamellae. The adults are characterized by: 1) vein CuP present and complete; 2) the ratio length of forceps segment I/forceps segment II 0.8; 3) penes subpyramidal, with a small apical furrow and with sclerotized yellowish lateral margins ( Fig. 24 ). The eggs are characterized by: 1) pear–shaped with one polar cap present ( Fig. 28 ).

Descriptions.

Mature nymph ( Figs. 1–23 ).

Length (mm): body, 4.2–4.8, caudal filament, 3.0–3.7, cerci, 2.2–2.6.

General coloration yellowish gray with black markings ( Fig. 2 ). Head shaded with gray mainly on occiput. Mouthparts: labrum with relatively shallow anteromedian emargination ( Fig. 3 ) with marginal row of stout bifid setae ventrally, and with pectinate setae dorsally as in figures 4 and 5; mandibles with setae on outer margin; hypopharynx with medially concave lingua, superlingua with a spine on inner margin at proximal third ( Fig. 9 ); maxillary palp small but elongated, 2 or 3 segmented with apical seta ( Figs. 6–8 ), distal brush of maxilla with 25–35 long and curved setae, with stipes 1.0 the length of galea–lacinia, inner proximal margin of the galea–lacinia (opposite to palpus) with row of 3–4 simple setae and one large pectinate seta ( Figs. 6 and 7 ); labium with paraglossae and glossae with the same length, lateral margin of prementum with 19–32 long and thin setae ( Fig. 10 ). Thorax. Pronotum yellowish shaded with gray, with small blunt tubercle medially ( Fig. 15 ) and pointed anterolateral projection ( Fig. 16 ). Mesonotum yellowish shaded extensively with gray, darker on anterolateral corners; wingbuds yellowish with black veins; small anteromedian blunt tubercle. Metanotum and thoracic sterna paler, not shaded. Legs yellowish, shaded gray on femora and with a proximal and a distal macula on tibiae. Foreleg: transverse row of long setae ( Fig. 11 ) located at 0.4–0.5 of total femoral length from base; total length (tl, same figure) / maximum width (mw) of femur = 2.4–3.1; fore tarsal claw with 10–13 marginal denticles and with 0–1 + 1 submarginal denticles ( Fig. 12 ). Middle and hind legs ( Figs. 13 and 14 ): femur covered with many long weak setae, some forming a proximal transversal row, other scattered over surface and margins; total length / maximum width of hind femur = 2.8–3.6; tarsal claw with 11–13 marginal denticles and 0–1 + 1 subapical sumarginal denticles. Abdomen. Yellowish shaded with gray widely,except on intersegmental membranes, darker on medial longitudinal line; small posterolateral spines present on segments VI–IX (smaller on IX), lateral flanges present on segments III–VI ( Fig. 17 ). Gill formula 3/3/3/3/2. Operculate gills subtriangular, shaded widely with irregular gray markings except on a paler area near insertion ( Fig. 18 ); gills III–VI with a pair of basal black marks, gills III–V with relatively wide ventral most lamellae ( Figs. 20–23 ). Caudal filaments yellowish white shaded with gray on basal segments.

Variations. The coloration is variable; some nymphs are pale with few dark markings, others are blackish or reddish ( Figs. 1 and 2 ). Operculate gills also vary in coloration: some nymphs present a basal black band and the rest homogeneously shaded with gray, others nymphs show blackish operculum.

Male imago ( Figs. 24–27 )

Length (mm): Body, 4.8–5.0, Fore wing, 5.0–5.5, Caudal filaments, 13.0, Terminal filament, 14.0–18.5.

General coloration gray brown. Head. Yellowish with gray shading on occiput. Pronotum. Medially whitish with longitudinal black stripe, meso– and metanotum brownish, mesopleura and meso- and metasternum brownish with lighter membranes ( Figs. 25 and 26 ). Legs. Whitish, coxae, trochanters and femora yellowish brown; tibiae and tarsi much paler; blackish shading medially and subapically on femora; tibiae with a basal and distal black macula; inner face of tibiae II and III with a medial black stripe along patellotibial suture ( Fig. 27 ). Fore wing. Translucent, veins shaded with gray, vein CuP complete. Abdomen. Brownish yellow with whitish intersegmental membranes black maculae present medially and also irregular gray shading on all terga. Sterna similar to terga with a medial black macula on each intersegmental membrane ( Figs 25 and 26 ). Genitalia. Styliger plate whitish with brownish hind margin. Forceps translucent. Penes subpyramidal, whitish yellow shaded with brown as in figure 24. Caudal filaments whitish translucent shaded slightly with gray.

Female imago. Length (mm): Body, 5.5, Forewing, 6.8. Coloration as in male except abdomen plenty of orangish eggs.

Eggs. Pear–shaped with disc-like polar cap on thinner pole ( Fig. 28 ).

Distribution. T. biluhue sp. nov. has a wide distribution in Uruguay as shown in figure 29.

Etymology. The epithet biluhue comes from the charrua language ”bilú hue” and means ”beautiful water”. We want to dedicate this species to the Uruguayan people and the Franciscan Family of this country who are demanding the repeal of the recently irrigation law that violates the human and biotic right to water.

Figures

FIGURES 1–2. Tricorythodes biluhue sp. nov. Nymph: 1, habitus; 2, idem variation.

FIGURES 3–14. Tricorythodes biluhue sp. nov. Nymph: 3, labrum, dorsal view (d.v.) right, ventral view (v.v.) left; 4, distal margin of labrum, d.v; 5, distal margin of labrum, v.v; 6, right maxilla, v.v and detail of palp; 7, left maxilla, v.v. arrow indicates detail of palp; 8, detail of maxillary palp, v.v. (figures 6–8 from different specimens); 9, hypopharynx, d.v., arrow indicates spine on inner margin of superlingua; 10, labium, v.v (left with setae, right setae omitted); 11, foreleg, d.v.; 12, fore tarsal claw; 13, middle tibia; 14, hind leg, d.v.

FIGURES 15–24. Tricorythodes biluhue sp. nov. Nymph: 15, pronotum and part of mesonotum, lateral view; 16, pronotum (only right half), d.v.; 17, abdominal sterna III–IX; 18, opercular gill, d.v.; 19, opercular gill, v.v; 20–23, gills III–VI, v.v. Male imago: 24, genitalia, v.v.

FIGURES 25–28. Tricorythodes biluhue sp. nov. Male imago: 25, dorsal habitus; 26, ventral habitus; 27, hind leg, d.v.; 28, egg.