Callibaetis (Callibaetis) guttatus Navás 1915

(Figs. 4 A–5D)

Callibaetis guttatus Navás 1915b: 120; Gillies 1990: 25; Da-Silva 1991: 346; Domínguez et al. 2006: 113; Nieto 2008: 232; Salles et al. 2010: 302; Lima et al. 2012: 306; Cruz et al. 2014: 30, Angeli et al. 2015: 199.

Callibaetis apicatus Navás 1917: 189 . (syn. by Gillies 1990)

Callibaetis bruchius Navás 1920b: 55 . (syn. by Gillies 1990)

Callibaetis zonatus Navás 1929: 224 . (syn. by Gillies 1990)

Known stages. I ♀♂, N

Diagnosis. Male imago: 1) dorsal portion of turbinate eyes oval; 2) dorsal portion of turbinate eyes in lateral view without constriction; 3) dorsal portion of turbinate eyes stalk height 1.9× height of dorsal portion; 4) turbinate portion of compound eyes (in lateral view) with anterior and posterior margins divergent; 3) forewing hyaline or with C, Sc, R1 and posterior margin areas with large marks; 4) marginal intercalary veins paired; 5) hind wing hyaline or with basal mark; 6) costal process of hind wing rounded; 7) marginal intercalary veins on hind wing present; 8) abdominal terga III, V and VII with lateral marks; 9) abdominal sterna with pair of medioanterior and medioposterior sigilla without pigment; 10) forceps segment I wide at base; 11) forceps segment III oval.

Female imago: 1) forewing at least with C, Sc, R1 and posterior margin areas with marks, maximal degree of pigmentation with seven complete and transversal bands (Fig. 5 C); 2) marginal intercalary veins paired (Fig. 5 C); 3) hind wing hyaline or with marks at base and middle (Fig. 5 D); 4) costal process of hind wing rounded; 5) marginal intercalary veins on hind wing present (Fig. 5 D); 6) abdominal terga II, III, V and VII with inverted V mark laterally (Fig. 5 A); 6) abdominal sterna with pair of medioanterior and medioposterior sigilla without pigment (Fig. 5 B); 7) abdominal terga and sterna with few or without spots (Figs. 5 A and 5B); 8) abdominal sterna medially on anterior margin without one large spot (Figs. 5 A and 5B); 9) abdominal terga without medial longitudinal mark (Figs. 5 A and 5B).

Mature nymph: 1) maxillary palp subequal in length than galea-lacinia; 2) below maxillary palp insertion on outer margin without tuft of robust spine-like setae (Fig. 29 in Nieto 2008); 3) paraglossa with row of spine-like setae on ventral surface (Fig. 30 in Nieto 2008); 4) segment III of labial apically rounded (Fig. 30 in Nieto 2008); 5) metanotum without spines; 6) foretarsus anterior surface without spine-like setae; 7) mid and hind claw denticles smaller than foreclaw denticles (Fig. 33 in Nieto 2008).

Comments. Nieto (2008) described variation in the fore- and hind wings of this species.

In the present work, the specimens illustrated in Figures 20, 21 a, 21b, 23, 24a and 24b in Nieto (2008) were examined. We conclude that they belong to C. (A.) fasciatus based on having forewing with three or four transverse bands of pigmentation, apical band transverse to posterior margin (see also Cruz et al. 2014 and comments for C. (A.) sellacki herein).

Callibaetis (C.) guttatus is similar to C. (C.) zonalis, C. (C.) willineri and C. (C.) jocosus . All four species share an inverted “V” mark on female abdominal terga III, V and VII and variable pigmentation on the female forewings. The female imago of C. (C.) guttatus can be differentiated from C. (C.) jocosus by the abdominal terga and sterna having few or no spots (Figs. 5 A and 5B); from C. (C.) willineri by the abdominal sterna lacking one large spot medially, on the anterior margins (Figs. 5 A and 5B); and from C. (C.) zonalis by abdominal terga without medial longitudinal mark (Figs. 5 A and 5B).

We present figures of the types of the two synonymized species (Figs. 4 A–4D) and newly collected specimens from Brazil (Figures 5 A–5D).

The specimens studied by Navás (1915b) from Prov. de Buenos Aires, Argentina, were not found, thus a lectotype was not designated.

Material examined. Male imago (type of Callibaetis apicatus), ARGENTINA, Buenos Aires, 15.v.1915, MZB ; one female imago (type of Callibaetis zonatus), ARGENTINA, Alta Gracia, 17.ii.1929, MZB ; one female imago ( Callibaetis guttatus), ARGENTINA, Alta Gracia, 27.vi.1926, C. Brush det., MZB ; one nymph, ARGENTINA: Tucumán, Depto. Tafí Viejo, Raco (km 19), A8 Palangana, 24.xi.2001 , C. Molineri coll.; one female imago reared, BRAZIL, Espírito Santo state, São Mateus, Rio São Mateus, 02.x.2007 , F. F. Salles coll., INPA.

Distribution. Argentina: Tucumán; Misiones; Buenos Aires; Alta Gracia. Brazil: Ceará; Espirito Santo; Rio de Janeiro; Pernambuco.