Ulmeritoides uruguayensis (Traver) Domínguez, 1991

Mariano, Rodolfo & Froehlich, Claudio G., 2007, Description of the nymph of Ulmeritoides uruguayensis (Traver) (Ephemeroptera: Leptophlebiidae), Zootaxa 1642, pp. 61-64 : 61-63

Ulmeritoides uruguayensis (Traver) Domínguez, 1991

Diagnosis. The nymph of U. uruguayensis can be distinguished from its congeners by the following differential characters: 1) middle tibia with an apical black spot; 2) glossa with digitate bristles on apex; 3) segment I and base of segment II of maxillary palpi brown; 4) posterolateral projections on abdominal segments II–IX.

Mature Nymph. Body length: 8.8 mm. Caudal filaments: 12 mm. General coloration: brown, dark brown and yellow. Head: dark brown with yellow spots; clypeus equal in width to labrum, anterior margin of clypeus almost straight. Antenna: yellow. Mouthparts: yellow and brown. Labrum ( Fig. 1 ): yellowish brown, anteromedian region wide, deep and U-shaped, with inconspicuous remains of four denticles and one middle larger denticle. Mandibles ( Fig. 2 ): yellow and brown with black spots, outer dorsal margin with fine bristles. Maxillae ( Fig.3 ): yellow; segment I and base of segment II of palpi brown, segment III of palpi ½ of the length of segment II, with tuft of bristles on apex and many bristles on apical region; 10–14 subapical pectinate setae. Labium ( Fig. 4 ): yellow; segment II of palpi similar in length to segment I and five times length of segment III; labium yellow with black spots on paraglossa and with many antero-dorsal bristles; glossa with digitate bristles on apex ( Fig. 5 ). Abdomen ( Fig. 6 ): brown and dark brown with lateral margin in yellow; posterolateral projections on abdominal segments II–IX. Thorax: dark brown with yellow spots. Legs: yellow. Fore leg ( Fig. 7 ): black spots on middle of femur, apex and part of base of tibia; femur with some plumose bristles ( Fig. 8 ) at base of inner margin, remaining bristles filiform, in the outer margin long bristles; inner surface of tibia with plumose bristles ( Fig. 8 ); apex of tarsal claws ( Fig. 9 ) hooked, narrow and brown, with small spines basally and progressively larger denticles apically. Middle leg ( Fig. 10 ): femur with a median black spot; tibia with bristles on the inner surface and long slender bristles on the outer margin; a black spot on the apex. Hind leg ( Fig. 11 ): femur with several dorsal bristles; tibia with row of bristles on the inner and outer surface, numerous plumose bristles at apical margin and a row of plumose bristles on the ventral side.

Material examined: 6 nymphs: Brazil, São Paulo State, Salesópolis, Estação Biológica de Boracéia, Córrego Venerando (23°39’14”S 45°53’28”W), 09-x-2004, Froehlich, C.G.; Mariano, R.L.S., Siegloch, A.E. and Silveira, G.A. 1 nymph: same data except Córrego Mutuca (23°38’22”S 45°50’49”W), 11-x-2004, Froehlich, C.G.; Mariano, R.L.S., Siegloch, A.E. and Silveira, G.A. 4 nymphs: same data except Córrego Venerando (23°39’14”S 45°53’28”W), 12-x-2001, Froehlich, C.G.; Mariano, R.L.S. and Polegatto, C. M. 2 nymphs: same data except Córrego Venerando (23°39’14”S 45°53’28”W), 26-iii-2003 Froehlich, C.G.; Mariano, R.L.S. and Spies, M.R. 1 nymph: same data except Ribeirão Coruja (23°40’05”S 45°53’57’’W), 28-iii-2003, Froehlich, C.G.; Mariano, R.L.S. and Spies, M.R. 5 nymphs: same data except Córrego Venerando (23°39’14”S 45°53’28”W), 27-iii-2003, Froehlich, C.G.; Mariano, R.L.S. and Spies, M.R. 1 nymph: same data except Córrego Mutuca (23°38’22”S 45°50’49”W), 27-iii-2003, Froehlich, C.G.; Mariano, R.L.S. and Spies, M.R. 5 nymphs: same data except Córrego Mutuca (23°38’22”S 45°50’49”W), 28-iii-2003, Froehlich, C.G.; Mariano, R.L.S. and Spies, M.R. 6 nymphs: same data except Córrego Venerando (23°39’14”S 45°53’28”W), 26-iii-2003, Froehlich, C.G.; Mariano, R.L.S. and Spies, M.R.

The material is deposited in Museu de Zoologia da Universidade de São Paulo, São Paulo State, Brazil (MZUSP).

Remarks. The nymphs were collected in leaf packs in pools of low order permanent stony bottom streams. U. uruguayensis adults were collected in the same places, thus providing an indirect association with the nymphs described here. Light trap collections at the same sites over six years have not provided any other Ulmeritoides species. The vegetation of the collection site (Estação Biológica de Boracéia) is Atlantic Rainforest.

The nymph of U. uruguayensis stands probably near U. oepa and U. misionensis by possessing a large middle denticle in the anteromedian emargination of the labrum; thus U. uruguayensis could be a third member of the species group proposed by Lopes et al. (2003). The main difference between the nymph of U. uruguayensis and the others congeners is a posterolateral projection on abdominal segments II–IX, instead of VI– IX, as described for the genus.

Figures

FIGURES 1 – 11. Ulmeritoides uruguayensis: 1, labrum; 2, left mandible (dorsal view); 3, right maxilla (ventral view); 4, labium (right ventral view, left dorsal view); 5, detail of glossa (ventral view); 6, abdominal color pattern; 7, fore leg; 8, plumose bristles; 9, tarsal claw (fore leg); 10, middle leg; 11, hind leg.