Americabaetis labiosus Lugo-Ortiz & McCafferty 1996
Creators: name: Salles, F. F.
name: Raimundi, E. A.
name: Boldrini, R.
name: Souza-Franco, G. M.
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Baetidae
Americabaetis
Americabaetis labiosus

description: Americabaetis labiosus Lugo-Ortiz & McCafferty, 1996   
(Figs. 1c, 14–17, 18, 21, 25, 29)  
 Americabaetis labiosus Lugo-Ortiz & McCafferty, 1996: 164; Francischetti et al., 2003: 69; Domínguez et al., 2006: 70; Salles et al., 2010: 302.   
 Diagnoses. Nymphs: 1) Frontal keel absent; 2) lingua broadly pointed apically; 3) glossa 0.6x length of paraglossa, 4) apex of paraglossa with rows of pectinate setae; 5) segment II of labial palp with a small distomedial projection; 6) posterior margin of abdominal terga with rounded spines.   
Male imago: 1) turbinate eyes anteriorly divergent and widely separated from each other, upper surface ellipsoidal (Fig. 14); 2) terga light whitish brown, lateral margins darker (Figs. 14, 15); 3) forceps with first segment constricted medioapically (Fig. 17); 4) posterior margin of subgenital plate with a small rounded projection (Fig. 17); 5) length of body relatively small (4.0 mm).  
 Description (Male imago). Measurements. Body 4.0 mm; forewing 4.0– 4.3 mm; antenna 0.7 mm; tibia I: 1.31 mm; tibia II: 0.88 mm; tibia III: 0.89 mm.   
 Head (Figs. 14–15). Coloration light brown with V shaped brown mark between compound eyes. Turbinate portion of compound eyes orangish; basal half of stalk brown, paler toward apex. Antenna light brown. Dorsal portion of turbinate eyes ellipsoidal; length 1.5x width; stalk height 0.5x width of dorsal portion; inner margins widely separated, divergent anteriorly.   
 Thorax (Figs. 14–15). Pro, meso and metanotum brown; submedioscutum light brown; scutellum dark brown. Sternum brown. Anteronotal protuberance rounded. Metascutellar protuberance pointed dorsally. Legs whitish. Leg I: tibia 1.7x length of femur; tarsi 1.6x length of femur; and with 4 segments decreasing on length apically. Leg II and III: tibia 1.4x length of femur; tarsi 0.4x length of femur. Forewing (Figs. 16) hyaline, posterior region of costal and subcostal veins grayish; veins Costal and subcostal light brown; stigmatic area with 6 cross veins not touching subcostal vein; marginal intercalary paired, except single between veins ICu1 and A; length of intercalary vein between IMA and IMA2 1.7x distance between adjacent longitudinal veins; length of forewing about 2.4x width.   
 Abdomen (Figs. 14–15). Terga light whitish brown, lateral margins darker; tracheation blackish. Sterna light whitish brown. Genitalia (Figs. 17) segment I whitish washed with brown, segments II and III whitish. Forceps segment I distinctly constricted medioapically; 0,5x length of segment II; distance between base of forceps 0,2x distance between lateral margins of forceps. Forceps segment II narrow submedially. Forceps segment III elongate, 2.7x as long as wide; 0.17x length of segment II. Posterior margin of subgenital plate with a small rounded projection.   
 Comments. In Brazil A. labiosus is apparently restricted to the southern area of the country. Their nymphs, as those of A. titthion and A. mecistognathus, sp. nov., inhabit shallow areas with moderate to fast current (Fig. 29). However, unlike these species, they are often associated with dead leaves above rocks. The altitudinal range of this species varies from 700 to 1900 m.a.s.l.   
 Distribution. PARAGUAY, URUGUAY, BRAZIL: Rio Grande do Sul, Paraná, Santa Catarina; Rio de Janeiro, Espírito Santo, São Paulo. NEW RECORDS: Minas Gerais (Fig. 1b).   
 Material examined. MINAS GERAIS, Chácara, Cachoeira Menezes, 16/i/2000, CNF & R. F. Rocha; ESPÍRITO SANTO, Santa Teresa, Nova Lombardia, Sítio Capitel de Santo Antônio, Córrego Grande, S 19°52’31.0” / W 40°31’49.1”, 768 m. a.s.l., 19-20/i/2008, 20/ii/2009, FFS col. (CEUNES). One male imago (reared), Brazil, ESPÍRITO SANTO, Alfredo Chaves Country, Nova Estrela, waterfall Petralonga, 20°39'76.6"S/ 40°50'72.6"W, 23.v.2008, RB col. One male imago and one male subimago (reared), Brazil, ESPÍRITO SANTO, Alfredo Chaves Country, Nova Estrela, waterfall Petralonga, 20°39'76.6"S/ 40°50'72.6"W, 20.ii.2009, RB col.
description: Published as part of Salles, F. F., Raimundi, E. A., Boldrini, R. & Souza-Franco, G. M., 2010, The genus Americabaetis Kluge (Ephemeroptera: Baetidae) in Brazil: new species, stage description, and key to nymphs, pp. 16-28 in Zootaxa 2560 (1) on page 23, DOI: 10.11646/zootaxa.2560.1.2, http://zenodo.org/record/5302607