Rivudiva minantenna Lugo-Ortiz & McCafferty, 1998

Salles, F. F., Nieto, C. & Cruz, P. V., 2020, New species of Rivudiva Lugo-Ortiz & McCafferty (Ephemeroptera: Baetidae) with comments on R. minantenna Lugo-Ortiz & McCafferty and R. trichobasis Lugo-Ortiz & McCafferty, Zootaxa 4786 (1), pp. 37-52 : 48-49

Rivudiva minantenna Lugo-Ortiz & McCafferty, 1998

Rivudiva minantenna Lugo-Ortiz and McCafferty (1998: 63) ; Salles et al. (2004: 727); Domínguez et al. (2006: 176); Salles & Nascimento (2009: 233).

Material examined. Paratype (slide #301 IBN): BRAZIL, Rio Grande do Sul state, Rio Santa Maria, S 31 o 10’ W 54 o 23’, 280 m. a.s.l., xi.1964, F Plaumann col. 3 nymphs, BRAZIL, Espírito Santo state, Linhares, Rio São José , S 19° 07’ 33.1’’, W 40° 14’ 26.1”, 20 m. a.s.l., 26.viii.2011, FF Salles leg. (1 UFVB, 1 IBN, 1 used for SEM images) .

Diagnosis

Nymph. 1) antenna without spine-like setae on scape and pedicel; 2) distal margin of labrum with deep, wide, medial emargination (as in Fig. 1 ); 3) dorsal surface of labrum with irregular row of setae; 4) tuft on apex of lingua formed by long simple setae (as in Fig. 4 ); 5) maxillary palp segment I long, reaching apex of galea-lacinia; 5) glossa with base ventrally expanded, apex narrow, obliquely truncate and with dorsal thick setae distomedially (as in Fig. 6 ); 6) hind wing pads present; 7) trochanter without robust, long and apically pointed setae; 8) outer dorsal row, medial dorsal row and inner dorsal row of femora with robust, long and apically pointed setae, those of outer row almost as long as maximum width of femur ( Fig. 32 ); 9) abdominal sterna without robust apically pointed setae; 10) paraproct with 10-12 marginal spines (according to original description).

Imago. Unknown.

Distribution. Brazil (Rio Grande do Sul, Santa Catarina, and Espírito Santo) ( Fig. 41 ).

Comments. This species was also reported from Rio de Janeiro by Salles et al. (2004). However, based on the new evidences presented here, it became clear that these specimens belong to an additional new species. As we only have a single mature nymph in good condition, we refrain from describing this species in the present paper.

Figures

FIGURE 41. Map of South America showing the distribution of the distinct species of Rivudiva.

FIGURES 1−6. Rivudiva inma, sp. nov., nymph: (1) Labrum; (2) Left mandible; (3) Right mandible; (4) Hypopharynx; (5) Maxilla; (6) Labium (left = ventral surface, right = dorsal surface).

FIGURES 30−37. Rivudiva spp. SEM photographs. (30) Fore femur of R. inma, sp. nov.; (31) Fore femur of R. inma, sp. nov., detail of outer margin; (32) Femur of R. minantenna; (33) Femur of R. trichobasis; (34) Tarsal claw of R. inma, sp. nov., inner view; (35) Tarsal claw of R. minantenna, lateral view; (36) Abdominal sternum of R. trichobasis; (37) Abdominal sternum of R. trichobasis, detail of setae.