Tricorythopsis acara, Belmont, Enide Luciana L., Salles, Frederico F. & Hamada, Neusa, 2011

Belmont, Enide Luciana L., Salles, Frederico F. & Hamada, Neusa, 2011, Three new species of Leptohyphidae (Insecta: Ephemeroptera) from Central Amazon, Brazil, Zootaxa 3047, pp. 43-53 : 47-50

Tricorythopsis acara sp. nov.

( Figs. 10–21 )

Diagnosis. This species can be distinguished from other species of the genus by the following combination of characteristics: nymph- 1) maxillary palp one segmented with terminal, apical setae; 2) tarsal claws with 5 marginal and 3+2 submarginal denticles, and with apical setae; 3) grayish abdominal pigmentation with areas whitish on middle part of tergites VI–VIII. Adult- 1) legs light brown with dark marks; 2) veins IMP and IMP2 of forewing joined by only one crossveins; 3) penes cylindrical, with similar width along their length; 4) lateral margins of penes sclerotized; 5) penes divided at apical 1/6.

Description. Mature nymph. Length: Body, 1.5–2 mm; Mesonotum, 0.5–0.76 mm; Caudal filaments, 1.4 mm. General coloration yellowish with brown marks. Body elongate, base of abdomen slightly wider than apex ( Fig. 10 ). Head: coloration yellowish with brown marks between ocelli; Antennae yellowish-translucent. Mouthparts yellowish; labrum with shallow anteromedial emargination ( Fig. 11 ); maxilla yellowish with pectinate setae; palp 1-segmented, 2 × longer than wide, with fine and long seta, and a terminal seta ( Fig.13 ); labium yellowish with many pores; glossa not fused, with flattened setae laterally fringed and simple setae; paraglossa ( Fig. 12 ) with simple and fringed setae ( Fig. 17, 18 ). Thorax: general coloration brown with pale yellowish regions. Tubercle on pronotum absent. Anterolateral corner of pronotum not projected; pronotum yellowish with brown marks. Tubercle on mesonotum absent; mesonotum yellowish with brown marks in anterior margin. Inner apical margin of forewing pads not elevated. Legs yellowish with three black bands; ratio of foreleg 1.6: 1(0.2): 1: 2; coxae projections absent ( Fig. 14 ); femur broad (as wide as long) ( Fig. 15 a); outer margin of femora with medium size setae; transversal row of elongate setae on anterior surface of fore femur on submedian region ( Fig. 15 a); tibiae with simple and pectinate setae; tarsal claws with 5 marginal and 3+2 submarginal denticles, with apical seta ( Fig. 16 ). Abdomen: general coloration yellowish with blackish marks, grayish abdominal pigmentation with areas whitish on middle part of tergites VI–VIII; posterolateral margin expanded on segments III–VI, with segment VII forming a posterolateral projection barely discernable. Operculate gills oval, yellowish with black mark on base; transvers line of operculate gill present; operculate gills reaching segment VI; gill formula 4/4/2/2/1. Caudal filaments translucent with brown marks and setae between the segments.

Imago. Length of male: Body, 1.3 mm; Forewing, 0.9 mm. General coloration. Light brown. Head: coloration light brown with a whitish area between ocelli. Compound eyes black. Antennae, scape and pedicel yellowish, flagellum hyaline. Thorax: brownish. Mesoscutellum with short and wide membranous filaments. Forewing opaque whitish with costal area darker; vein CuP entire, reaching posterior margin; ICu2 present; veins MA and MP of forewing joined by only one crossveins ( Fig. 21 ). Legs light brown with apical dark marks on femora. Abdomen: similar to nymph. Genitalia with styliger plate yellowish; forceps base short, about as long as length of forceps segment 1; penes long, cylindrical, with similar width along their length ( Fig. 20 ); lobes apically rounded and lateral margins sclerotized ( Fig. 20 ); divided on apical 1/6, with wide apical suture; spines of penes absent. Caudal filaments brownish.

Life cycle associations. The association between male imago and nymphs was made by shared abdominal color pattern of specimens collected in the same stream.

Biological aspects. Nymphs were found in roots in areas with fast-flowing water. Imagos emerge at dawn and were easily collected with a Pennsylvania trap.

Etymology. Acará is the name of the stream, in Adolpho Ducke Forest Reserve, where this new species was first collected.

Discussion. The nymphs of Tricorythopsis acara sp. nov. are very similar to those of T. minimus Allen, 1973 and T. chiriguano Molineri, 2001 , but they can be differentiated in the nymphal stage by color pattern, tarsal claws denticulation, and characteristics of the maxillary palp. In adults they can be distinguished by venation of wings and shape of penes.

Material examined. Holotype: Nymph (in alcohol), Brazil, Amazonas, Manaus, Reserva Florestal Adolpho Ducke, igarapé Acará (02º57'07.1"S / 059º57'28.7"W) iv-2010, Belmont, E.L.L. coll. ( INPA); Paratypes: 4 nymphs (in alcohol), Brazil, Manaus, Reserva Florestal Adolpho Ducke, igarapé Barro Branco (02º 55'46.7"S / 059º 58'22.0"W), iv-2010, Belmont, E.L.L. leg. ( INPA); 3 nymphs (in alcohol), Brazil, Presidente Figueiredo, AM-240, Balneário Recanto da Pantera, igarapé da onça, km 20 (02º00'52"S / 060º06'43"W), x-2009, Belmont, E.L.L., Cruz, P.V., Boldrini, R. coll. (CEUNES).

Figures

FIGURES 10 – 14. Tricorythopsis acara sp. nov. 10. nymph; 11. labrum (left d. v. and right v. v.); 12. labium (left d. v. and right v. v.); 13. right maxilla, maxilary palp in detail; 14 a. left mandible (d. v.); 14 b. right mandible (d. v.).

FIGURES 15 – 21. Tricorythopsis acara sp. nov. 15 a. foreleg; 15 b. midleg; 15 c- hind leg; 16. anterior tarsal claw; 17. pectinate seta; 18. simple seta; 19. short simple sete; 20. genitalia; 21. forewing.