Caenis ludicra Navas

Molineri, Carlos & Malzacher, Peter, 2007, South American Caenis Stephens (Ephemeroptera, Caenidae), new species and stage descriptions, Zootaxa 1660, pp. 1-31 : 16-21

Caenis ludicra Navas ( Figs. 66–85 , 149–150 , 161 , 169, 177)

Caenis ludiera [sic] Navas, 1920: 54 (male); Alba-Tercedor & Peters, 1985: 219. Caenis ludicra ; Navas, 1922: 199; Navas, 1924: 359; Navas, 1930a: 130; Navas, 1930b: 360; Navas, 1931: 322; Hub-

bard, 1982: 261; Domínguez, 1989: 272; Malzacher, 2001: 6 (male, nymph). Ordella ludicra ; Lestage, 1931: 59.

Type material. Not revised, but the material listed below was determined by comparison with the lectotype ( Malzacher, 2001). Four male imagos from ARGENTINA : Córdoba, San Esteban, 10-X-1981, E. Domínguez col.; 14 male and 1 female (female not listed in Malzacher, 2001) imagos from Tucumán, Lules, arroyo Las Vertientes, 28-VIII-1981, E. Domínguez col. ( IFML).

Additional material ( IFML). ARGENTINA : Córdoba, Río Cuarto, Paso del Cuco, Rodeo Viejo, 8-X- 1993, M. Gualdoni col.; Córdoba, San Esteban, río San Esteban, S 27° 15' – W 65° 32', 1-X-1999, V. Manzo & S. Cohen cols.; Córdoba, Cavalanga, Arroyo Las Salinas, S 31° 23' – W 64° 32', 2-X-1999, V. Manzo & S. Cohen cols.; Catamarca, Guayamba, río El Durazno, S 28° 21' 06" – W 65° 25' 53", 670 m, 8-II-2000, C. Molineri col.; Catamarca, dpto. Andalgalá, Las Estancias, El Lindero, S 27° 28' 01" – W 66° 00' 37", 1530 m, 19-IV-2003, E. Domínguez & G. Cuezzo cols.; Catamarca, Bañado de Ovanta, S 28° 08' – W 65° 19', 24-VIII- 2004, M. Peralta col.; Tucumán, Las Salas, río San Javier, 7-X-1998, E. Domínguez; Tucumán, Escaba, río Singuil, 12-XI-1999, C. Molineri col.; Tucumán, El Siambón, arroyo de la Gomería, 22-VIII-2004, C. Molineri col.; Tucumán, Raco, arroyo Palangana, VII-2004, CM; Tucumán, Dique El Cadillal, Ticucho, 12-X-1998, C. Molineri col.; Tucumán, Tafí del Valle, La Angostura, río Los Sosa, 2000 m, 5-XI-1995, C. Molineri col.; Salta, Finca Jakúlica, S 22° 41' 01" – W 64° 30' 40", 630 m, 14-XII-1999, E. Domínguez; Salta, Los Toldos, 27-X-1983, E. Domínguez; Salta, P. N. Baritú, río Baritú, 16-IX-1981, E. Domínguez; Salta, Vaqueros, río Calderas, S 24° 39' 45" – W 65° 23' 02", 1260 m, 2-III-2000, C. Molineri col.; Salta, Guachipas, río Grande del Sauce, 15-IX-1998, C. Molineri col.; Jujuy, San Salvador de Jujuy, río Lozano, 26-VI-1997, CM; Jujuy, Tiraxi, río de las Capillas, 27-XII-1998, W. Ciares & C. Rueda cols.; Jujuy, Palpalá, río Zapla, 26-VI-1997, C. Molineri col.; Jujuy, El Carmen, arroyo Las Lanzas, S 24° 27' 17" – W 65° 17' 48", 1250 m, 3-III-2000, E. Domínguez & C. Molineri col. BOLIVIA: Tarija, O'Connor, ca. Entre Ríos, río Salinas, 1160 m, S 21° 38' 45" – W 64° 09' 08", 6-X-2004, C. Molineri col.; same except río Saicán, 1000 m, S 21° 46' 28" – W 64° 05' 24", 7-X-2004, C. Molineri col.; Tarija, Arce, ca. La Mamora, río Orosa, 1100 m, S 22° 12' 09" – W 64° 37' 37", 5- X-2004, C. Molineri col.; Tarija, Quebrada el Molino, río Molino, S 21° 35' 35.7" – W 64° 46' 4.7", 1907 m, 25-II-2006, C. Nieto & P. Rueda cols.; Tarija, río Villa, S 21° 22' 57.8" – W 64° 16' 55.1", 1816 m, 5-III-2006, E. Domínguez & C. Nieto cols.; Tarija, Sidras, río Itaú, S 22° 05' 37.1" – W 63° 59' 12.7", 593 m, 8-III-2006, E. Domínguez & C. Nieto cols.

Male imago. As Malzacher (2001) reported, male imagos of C. ludicra show an almost circular central sclerite of the styliger plate, and the general coloration is generally very dark. Nevertheless, some populations in NW Argentina may show a lighter general coloration. Here the description of the female imago and nymphs of C. ludicra based upon reared material from both sexes is presented. Description and figures of male imago should be consulted from Malzacher (2001).

Female imago. Length: fore wings, 4.0– 5.3 mm; body, 4.7–5.7 mm; caudal filaments, 3.3–3.5 mm. General coloration orangish-brown to dark grayish-brown. Head: occiput with grayish reticulated marks. Femora without marks but sometimes femora II and III with small grayish subapical spots. Pronotum with a pair of submedian whitish circular marks. Mesothoracic katepisternum much lighter than the rest of mesothorax.

Abdominal terga uniformly shaded brownish-gray on paramedian marks; gill sockets paler; terga VII–IX with oval pale marks on lateral margins, similar contiguous marks present on sterna. Thoracic and abdominal sterna without well marked spots, specially on lateral margins; lateral filaments of abdomen medium length. IX sternum apically rounded. Caudal filaments whitish except basal and subbasal segments yellowish-brown.

Mature nymph ( Fig. 161 ). Length of male: body, 4.0–5.0 mm; caudal filaments, 3.2–3.5 mm. Length of female: body, 6.0– 6.3 mm; caudal filaments, 3.5–4.7 mm. Head paler on occiput, with submedian grayish marks (Fig. 169); hind margin of head with small frayed microtrichia. Mouthparts: segment II of labial palp 1.63–1.82 times the length of segment III. Thorax. Thorax yellowish to brownish, gray to black shading (variable). Pronotum with a pair of submedian large pale areas ( Fig. 161 ). Mesonotum with one pair of submedian pale blotches, and another pair on wingpad bases ( Fig. 161 ). Metanotum and thoracic sterna paler than dorsum. Legs: meso- and metacoxal processes well developed ( Figs. 66–67 ); femora only with slightly gray spots on subapex ( Figs. 83–85 ), femora with numerous weak setae at dorsum, dorsum of femora I with a transverse row of 6–8 setae at apical 1/3 ( Figs. 79, 83 ); tibiae and tarsi with basal band very slightly darker than the rest; all tarsi with a marginal row of spine-like setae, tarsi III with an additional submarginal row of serrated setae ( Fig. 81 ); tarsal claws relatively straight ( Figs. 71–73 ) to very slightly curved apically ( Figs. 68–70 ), tarsal claws I–II with 4–6 denticles ( Figs. 69–70, 72–73 ), tarsal claw III with 27–33 denticles ( Figs. 68, 71 ). Abdomen. Paler areas on abdominal terga generally forming a pair of submedian pale bands on segments VII–IX ( Fig. 175 ). Abdominal sterna shaded with gray but generally without distinct dark spots (similar to Fig. 184 ). Operculate gills generally without darker spots, uniformly brown; dorsal microtrichia bifid, widely subdivided ( Fig. 74 ), stout microtrichia on ventral submarginal row ( Fig. 75–76 ). Gills III–VI bicolor, half white and half gray. Sternum IX rounded apically, setae on hind margin strong and apically bent inwards. Caudal filaments whitish, darker only at basal segment.

Diagnosis. Caenis ludicra can be distinguished from the other species of Caenis by the following combination of characters. In the imago: 1) general coloration blackish-brown; 2) prosternal triangle anteriorly truncated in both sexes; 3) median filament on abdominal tergum II long; 4) fore legs 0.9–1.1 times length of body; 5) forceps apically rounded; 6) central sclerite of styliger circular; 7) apophyses of styliger sclerite short and rounded; 8) penis lobes rounded, more or less tapering, hind margin convex; 9) coloration of mesothoracic katepisternum paler than rest of mesothorax. In the nymph: 1) head color pattern as in Fig. 169, hind margin with small frayed microtrichia; 2) meso- and metacoxal processes present and pointed ( Figs. 66–67 ); 3) tarsi with relatively stout setae, only few of them serrated; 4) tarsal claws generally not strongly curved apically ( Figs. 68–73 ); 5) abdominal color pattern as in Fig. 175 ; 6) labrum with slightly rounded lateral margins; 7) segment II of labial palp 1.63–1.82 times the length of segment III; 8) lingua of hypopharynx with concave fore margin (similar to Fig. 156 ); 9) IX sternum rounded apically, setae on hind margin strong and apically bent inwards; 10) microtrichia from dorsum of body and operculate gills ramified ( Fig. 74 ); 11) gills III–VI bicolor, half white and half gray.

Two species are sympatric with C. ludicra , C. argentina and C. dominguezi . In C. ludicra pale blotches are less extended than in C. argentina (the most distinct are a submedian pair on mesonotum); and the occiput show dark pigments (Fig. 169), not present in C. dominguezi (Fig. 167).

Discussion. Malzacher (2001) described nymphs of " C. ludicra group" from Brazil, as probably pertaining to C. ludicra , but this species appears to be restricted to Southern Bolivia and Northwestern Argentina . The nymphs described by Malzacher are very similar to C. ludicra nymphs but represents another species (see C. uruzu new species, below).

Distribution ( Fig. 187). Argentina (Córdoba, Catamarca, Tucumán, Salta, Jujuy), Bolivia (Tarija). This species, quite common in NW Argentina , was also collected in Southern Bolivia. The distributional records include localities from mountain rain forest (Yungas), and drier habitats as Chaco, Monte and transitional regions.

Caenis plaumanni Malzacher (86–95, 151–152, 163, 170, 177, 183)

Caenis plaumanni Malzacher, 2001: 13 (male, nymph).

Material ( IFML). One male imago and 5 nymphs from ARGENTINA : Misiones, 10 km NE de San Vicente, INTA Cuartel Victoria, 30-XI-1986, E. Domínguez col.; 1 male imago Misiones, P.P. Urugua-í, arroyo Uruzú , S 25º 51' – W 54º 10', 322 m, 23-24-XI-1998, E. Domínguez et al. cols.; 4 nymphs Misiones, 25 km S El Soberbio, 21-XI-1998, E. Domínguez et al. cols.; 1 nymph Misiones, Candelaria, 2 km E Bonpland, río del Camping, 15-II-1985, E. Domínguez col.; 1 nymph idem before except date 18-XI-1998; 7 nymphs Misiones, 15 km E San José, RP 203, arroyo San Juan, 17-XI-1998, E. Domínguez et al. cols.; 2 nymphs Misiones, San Pedro, confluencia ríos Alegría y Pirai-Guazu, 22-23-XI-1998, E. Domínguez et al. cols.; and 2 nymphs Misiones, INTA Cerro Azul, arroyo Tacuará, 17-XI-1998, E. Domínguez et al. cols.

Descriptions of male imagos and nymphs of C. plaumanni can be found in Malzacher (2001).

Diagnosis. Malzacher (2001) had thoroughly described the male imago. Caenis plaumanni , known from male imagos and nymphs, can be distinguished from the other species of Caenis by the following combination of characters. In the imago: 1) general coloration yellowish brown; 2) prosternal triangle anteriorly pointed or rounded; 3) median filament on abdominal tergum II long; 4) fore legs 1.1 times length of body; 5) forceps apically rounded ( Figs. 7 c–e in Malzacher 2001); 6) central sclerite of styliger subcircular ( Fig. 7 a in Malzacher 2001); 7) apophyses of styliger sclerite long, thin, and relatively far from forceps bases; 8) penes lobes rounded, hind margin convex. In the nymph ( Fig. 163 ): 1) head color pattern as in Fig. 170, hind margin with scale-shaped microtrichia, surface of the head completely covered by short triangular spinules; 2) meso- and metacoxal processes semicircular ( Fig. 92 ); 3) middle and hind tarsi with one row of simple setae, and another of serrated setae; 4) tarsal claws generally curved apically ( Figs. 86–88 ); 5) abdominal color pattern as in Figs. 177 and 183 ; 6) labrum with slightly rounded lateral margins; 7) segment II of labial palp 1.55–1.68 times the length of segment III; 8) lingua of hypopharynx with concave fore margin (similar to Fig. 156 ); 9) IX sternum apically rounded, setae on hind margin strong and apically bent inwards; 10) scale-shaped microtrichia present on dorsum of body and gills II ( Figs. 8 i–j in Malzacher 2001).

Distribution ( Fig. 187). Argentina (Misiones) , Brazil (Rio Grande do Sul).

Figures

FIGURES 66 – 85. Caenis ludicra, nymph. 66, middle coxa; 67, hind coxa; 68, hind claw; 69, middle claw; 70, foreclaw; 71, hind claw; 72, middle claw; 73, foreclaw; 74, microtrichia on dorsum of operculate gill; 75 – 76, microtrichia on submarginal ventral row of operculate gill; 77, seta on posterior margin of hind tibia; 78, seta on posterior margin of hind tarsi; 79, setae on dorsal transverse row of fore femora; 80, microtrichia on dorsum of hind femora; 81, seta on hind tarsi; 82, seta of posterior margin of hind femora; 83, foreleg; 84, middle leg; 85, hind leg.

FIGURES 139 – 157. Left and right mandibles, d. v.: 139 – 140, C. argentina; 141 – 142, C. burmeisteri; 143 – 144, C. dominguezi; 145 – 146, C. gonseri; 147 – 148, C. tenella; 149 – 150, C. ludicra; 151 – 152, C. plaumanni; 153 – 154, C. uruzu. Hypopharynx, v. v.: 155, C. burmeisteri; 156, C. dominguezi; 157, C. tenella.

FIGURES 158 – 161. Nymph, general view: 158, C. argentina; 159, C. burmeisteri; 160, C. dominguezi; 161, C. ludicra.

FIGURES 172 – 178. Nymph, abdominal terga: 172, C. argentina; 173, C. burmeisteri; 174, C. dominguezi; 175, C. ludicra; 176, C. tenella; 177, C. plaumanni; 178, C. uruzu.

FIGURES 179 – 184. Nymph, abdominal sterna: 179, C. argentina; 180, C. burmeisteri; 181, C. dominguezi; 182, C. tenella; 183, C. plaumanni; 184, C. uruzu.

FIGURES 1 – 14. Caenis argentina, nymph. 1, middle coxa, d. v.; 2, hind coxa, d. v; 3, foreclaw; 4, middle claw; 5, hind claw; 6, microtrichia on dorsum of gill II; 7 – 8, microtrichia on ventral submarginal row of gill II; 9, setae on longitudinal row of middle and hind tarsi; 10, setae on subapical dorsal row of fore femora; 11, setae on longitudinal row of foretarsi; 12, foreleg; 13, middle leg; 14, hind leg.

FIGURES 162 – 164. Nymph, general view: 162, C. tenella; 163, C. plaumanni; 164, C. uruzu.

FIGURES 86 – 95. Caenis plaumanni, nymph. 86, foreclaw; 87, middle claw; 88, hind claw; 89, seta on transverse dorsal row of fore femora; 90, seta on dorsum of hind femora; 91, seta on hind tarsi; 92, hind coxa, detail 93, fore leg; 94, middle leg; 95, hind leg.