Additions and corrections to the systematics of mayfly species assigned to the genus Callibaetis Eaton 1881 (Ephemeroptera: Baetidae) from South America Author Cruz, Paulo Vilela Author Salles, Frederico Falcão Author Hamada, Neusa text Zootaxa 2017 4231 4 500 534 journal article 36559 10.11646/zootaxa.4231.4.2 fb0a7416-8d2e-4793-9dc3-525ffccb9e62 1175-5326 292674 99D539A1-D4BF-48C4-AEE1-0CA8F198C631 Callibaetis ( Callibaetis ) radiatus Navás 1920 ( Figs. 11 A–14D) Callibaetis radiatus Navás 1920a : 132 ; Gillies 1990 : 26 ; Salles et al. 2003 : 13 ; Domínguez et al. 2006 : 116 ; Cruz et al. 2014: 58; García 2014 : 41 ; Lima et al. 2016 : 214 ; Vinasco-Mondragón & Zúñiga 2016 : 92 . Callibaetis venulosus Navás 1933 : 114 . (syn. by Gillies 1990 ) Known stages. I ♀♂, N . Diagnosis. Male imago: 1) dorsal portion of turbinate eye oval ( Fig. 21 in Salles et al. 2003 ); 2) dorsal portion of turbinate eyes without constriction; 3) height of dorsal portion of turbinate eye stalk 0.85 × height of dorsal portion; 4) turbinate portion of compound eyes (in lateral view) with divergent anterior and posterior margins; 5) forewings hyaline (Fig. 167 in Cruz et al. 2014); 6) thick cross veins in C and Sc areas (Fig. 167 in Cruz et al. 2014); 7) marginal intercalary vein single (Fig. 167 in Cruz et al. 2014); 8) hind wing hyaline (Fig. 168 in Cruz et al. 2014); 9) hind wing with quadrangular costal process (Fig. 168 in Cruz et al. 2014); 10) hind wing with thick cross veins (Fig. 168 in Cruz et al. 2014); 11) marginal intercalary veins present on hind wing (Fig. 168 in Cruz et al. 2014); 12) abdominal terga with black mark anterolaterally (Fig. 169 in Cruz et al. 2014); 13) abdominal sterna with a weakly pigmented medioanterior and medioposterior sigilla (Fig. 172 in Cruz et al. 2014); 14) segment I of forceps wide at base (Fig. 166 in Cruz et al. 2014); 15) segment III of forceps truncated apex (Fig. 166 in Cruz et al. 2014). Female imago: 1) forewing with brown pigmented C, Sc and R1 areas, extending beyond R1 but not forming bands ( Fig. 11 C); 2) forewing with thick and black cross veins in C and Sc areas ( Fig. 11 B); 3) marginal intercalary veins single ( Fig. 11 C); 4) hind wing hyaline (Fig. 171 in Cruz et al. 2014); 5) hind wing with quadrangular costal process (Fig. 171 in Cruz et al. 2014); 6) marginal intercalary veins on hind wing present (Fig. 171 in Cruz et al. 2014); 7) hind wing with thick cross veins (Fig. 171 in Cruz et al. 2014); 8) abdomen with brown spots; 9) anterolateral spot on abdominal terga and sterna present (Figs. 169 and 172 in Cruz et al. 2014); 10) abdominal sterna with a weakly pigmented medioanterior and medioposterior sigilla (Fig. 172 in Cruz et al. 2014). Mature nymph: 1) maxillary palp 1.2 × length of galea-lacinia ( Fig. 12 F); 2) tuft of robust spine-like setae below insertion of maxillary palp absent ( Fig. 12 F); 3) ventral surface of paraglossa with row of spine-like setae ( Fig. 12 G); 4) segment III of labial palp rounded apically ( Fig. 12 G); 5) metanotum without spines; 6) anterior surface of foretarsus without spine-like setae ( Fig. 13 A). Redescription . Mature nymph: Length: body, 7.2–8.0 mm; broken cerci and terminal filament (n=1). Head . Coloration: faded in alcohol. Turbinate portion of male compound eyes yellowish brown. Antenna with small spines and fine, simple setae ( Fig. 12 A). Labrum ( Fig. 12 B) maximum length about 1.4 × maximum width; anterolateral margins with long spine-like setae; distal margin with spine-like setae medially; dorsal surface with many, long, fine and simple setae; distal margin with one row of fine spine-like setae ventrally; ventral surface with short, spine-like setae near lateral margin. Right mandible ( Fig. 12 C) with 4 + 3 denticles; margin between prostheca and mola convex; basal half with short, fine, simple setae and pores scattered over dorsal surface. Left mandible ( Fig. 12 D) with 4 + 2 denticles; margin between prostheca and mola straight; basal half with short, fine and simple setae and pores scattered over dorsal surface. Hypopharynx ( Fig. 12 E). Lingua with lobe covered with small simple setae; short, fine and simple setae scattered over distal margin of superlingua. Maxilla ( Fig. 12 F). Medial protuberance of galea with 1+ 3 spine-like setae. Maxillary palp short, 1.2 × length of galea-lacinia; palp segment II 1.2 × length of segment I; outer margin of segment I scattered with long, fine, simple setae; inner margin of segment II with few spine-like setae. Labium ( Fig. 12 G). Glossa subequal in length to paraglossa; inner margin with 11 spine-like setae; apex with 3 – 5 long spine-like setae; outer margin with row of long spine-like setae; dorsal surface with one row of long spine-like setae near outer margin and one tuft of setae at apex. Paraglossa. Ventral surface with one row of fine and simple setae; dorsal surface with three rows of long spine-like setae. Labial palp with segment I 1.1 × length of segments II and III combined; segment I covered with micropores; inner and outer margin of segment II with six spine-like setae; dorsal surface with row of six short spine-like setae; segment III with rounded apex. Thorax. Foreleg ( Figs. 13 A). Ratio of foreleg segments 0.9:1:0.6:0.3. Forefemur. Length about 4.0 × maximum width; dorsal margin with row of short, spine-like setae; apex with two robust spinelike setae; length of setae about 0.1 × maximum width of femur; anterior surface near dorsal margin with one row of spine-like setae. Tibia. One row of short spine-like setae ventrally; anterior surface with few fine and simple setae. Tarsus. Anterior and posterior surface without spine-like setae. Tarsal claw 0.5 × length of tarsus ( Figs. 13 B). Femur of hind leg without trifid setae; tarsal claw with small denticles ( Fig. 13 C). Abdomen. Terga. Posterior margin with regular spines ( Fig. 14 A). Sterna. Surface with fine, simple setae. Paraproct ( Fig. 14 B) with 24 marginal spines; surface with micropores and short, fine, simple setae. Cercus and terminal filament at base as in Figures 14 C and 14D respectively. Comments. The female imagoes of C. ( C. ) radiatus , C. viviparus and C. camposi are similar and could not be distinguished based on re-evaluation of the morphological evidence. However, as stated in the comments of C. camposi , the type locality of C. viviparus can be accessed and new specimens can be collected in the future. García (2014) recorded C. ( Callibaetis ) radiatus in Venezuela based on reared specimens (female, male and its nymphal exuviae). Taking into account the similarity between C. ( C. ) radiatus , C. viviparus and C. camposi and, in order to enable the comparisons to confirm this record, we re-describe and present new diagnosis and illustrations of the nymph described by Salles et al. (2003) , as well figures of the specimen originally described by Navás (1920), here designated as lectotype ( Figs. 11 A–11D). FIGURE 11. Callibaetis ( Callibaetis ) radiatus female imago (lectotype). A. labels; B. detail of anterior margin of forewing; C. forewing; D. dorsal view of body and wings. FIGURE 12. Callibaetis ( Callibaetis ) radiatus nymphs. A. antenna; B. labrum (left d.v., right v.v); C. right mandible; D. left mandible; E. hypopharynx; F. maxilla; G. labium (left d.v., right v.v.). FIGURE 13. Callibaetis ( Callibaetis ) radiatus nymphs. A. foreleg; B. foreclaw; C. hind claw. FIGURE 14. Callibaetis ( Callibaetis ) radiatus nymphs. A. posterior margin of terga IV; B. paraproct; C. cercus; D. terminal filament. Recently, Lima et al. (2016) and Vinasco-Mondragón & Zúñiga (2016) recorded C. ( C. ) radiatus respectively from Bahia state ( Brazil ) and Colombia , all based on female imagoes. Taking into account the morphological evidence here presented, both 2016 records of C. radiatus could be applicable to C. viviparus or C. camposi . Associations between stages should be made in order to confirm or refute these records. Material examined. Callibaetis radiatus , photographs of one female imago ( lectotype by present designation), Argentina , Santa Fé , 1.iii.1918 , MNHN ; one female imago, Argentina , Formosa , Reserva EL , Bagual , xi-2004 , Serochi coll.; one female imago, Paraguay , Asunción , 15.x.1919 , MZB ; male imago, female imago (reared) and two nymphs, BRAZIL , Minas Gerais , Viçosa , Ranário—Universidade Federal de Viçosa , 27.i.1997 , E.R. Silva coll. Distribution. Argentina : Santa Fé . Paraguay : Asunción . Brazil : Bahia ; Minas Gerais .