Paracloeodes charrua, Emmerich & Nieto, 2009

Emmerich, Daniel & Nieto, Carolina, 2009, First record of the genus Paracloeodes Day (Ephemeroptera: Baetidae) in Uruguay and description of two new species, Zootaxa 2225 (1), pp. 57-62 : 58-60

Paracloeodes charrua sp. nov.

( Figs. 1–12 )

Nymph. Length: body: 3.8–4.3 mm; cerci 1.8 mm. Antennae long, 2.1 mm, 3.5 times width of the head capsule. General color yellowish brown. Head yellowish brown with a characteristic pattern ( Fig. 1 ). Frontal keel present, ocelli black. Antennae pale yellow. Mouthparts ( Figs. 2–7 ): labrum ( Figs. 2 a–b ) dorsally with a pair of subapical setae near midline, anterior margin with bifid setae. Mandibles ( Figs. 3–4 ) without setae between prostheca and mola, incisors cleft in two sets, inner set at right angle with outer set. Left mandible ( Fig. 3 ) with molars with constrictions, prostheca with two denticles. Right mandible ( Fig. 4 ) with prostheca slender and bifid. Hypopharynx with lingua shorter than superlinguae and rounded apically. Maxillae ( Fig. 6 ) with palpi two-segmented, twice the length of galea-lacinia. Labium ( Fig. 7 ) with segment II of palpi with rounded projection, 2 times width of segment III, segment III conical.

Thorax yellowish brown, shadowed with brown ( Fig. 1 ). Pleura brownish, sterna pale yellow. Legs ( Fig. 8 ) pale yellow, femora with brownish transverse band apically (more conspicuous in female). Tarsal claws ( Fig. 9 ) 0.5 times the length of tarsi, with 2 rows of small denticles basally and 4–5 denticles increasing in size apically. Hind wing pads present.

Abdomen yellowish brown ( Fig. 1 ). Color pattern: segment II–IX with 3 brownish spots forming a triangle, segment V and IX darker than others. Posterior margin of terga with spines 2 times longer than wide ( Fig. 10 ). Sterna yellowish brown, sternum IX darker than others. Gills whitish, elongate, less than twice the length of each tergum, main branch of trachea pigmented. Paraprocts ( Fig. 11 ) with 10–12 spines apically. Terminal filaments with crown of spines on each segment, cerci with long spines toward the external margin every four segments ( Fig. 12 ).

Adults. Unknown.

Etymology. Charrua: ethnic group that inhabited Uruguay and was exterminated in the middle of the 19th Century. We dedicate this species to their memory.

Discussion. This species can be distinguished from the other species of the genus by the following combination of characters: 1) frontal keel present; 2) antennae long, 3.5 times width of head capsule; 3) maxillae with palpi twice the length of galea-lacinia ( Fig. 6 ); 4) segment II of labial palpi with rounded projection, 2 times width of segment III ( Fig. 7 ); 5) tarsal claws 0.5 times the length of tarsi with two rows of small denticles basally and 4–5 denticles increasing in size apically ( Figs. 8–9 ); 6) hind wing pads present; 7) abdomen with a characteristic color pattern: segment II–IX with 3 brownish spots forming a triangle ( Fig. 1 ); 8) posterior margin of terga with spines twice longer than wide; 9) paraprocts with 10–12 spines apically; 10) cerci with long spines toward the external margin every four segments ( Fig. 12 ).

Material. Holotype, female nymph: URUGUAY, Depto. Cerro Largo, Arroyo Otazo , ruta 8, km 335, S 32°50´00´´, W 54°14´55´´, 123 m. 20/02/2008, Emmerich & Molineri cols . Paratypes: 4 nymphs same data (mouthparts, legs and paraprocts of one nymph mounted on slides); 4 nymphs: Depto. Rivera, Tranqueras, ruta 30, km 251, Río Tacuarembó, S 31°10´40´´, W 55°45´44´´, 147 m, 19/02/2008, same collectors; 5 nymphs: Depto. Tacuarembó, ruta 5, km 379, A° Tranqueras, S 31°47´29´´, W 55°58´51´´, 124 m, 22/02/ 2008, same collectors; 3 nymphs: Dpto Soriano, ruta 21, km 339, Aº Las Maulas, S 33º 23’ 32’’, W 58º 07’ 02’’, 16 m, 6/03/08, Emmerich & Pérez cols.; 11 nymphs: Dpto Paysandú, “Predio”, Aº Grande, S 32º 39’ 34.2’’, W 57º 14’ 56.7’’, 9/08/07, Morelli col. The holotype is deposited in the Museo de la Universidad de la República, Montevideo Uruguay ( MUR), paratypes are deposited in Instituto Miguel Lillo, Tucumán, Argentina ( IML) .

Figures

FIGURES 1–12. Paracloeodes charrua sp. n. Nymph. 1, General view. Mouthparts (Figs. 2–7): 2a, labrum, left d.v., right v.v.; 2b, labrum: apical setae; 3, left mandible v.v.; 4, right mandible v.v.; 5 hypopharynx v.v.; 6, maxilla v.v.; 7, labium, left d.v., right v.v.; 8, leg I; 9, tarsal claw I; 10, posterior margin of tergum IV; 11, paraproct; 12, caudal filament detail; 12a, left cercus; 12b, terminal filament.