Campsurus indivisus Ulmer, 1942

Molineri, Carlos & Salles, Frederico F., 2017, Review of selected species of Campsurus Eaton 1868 (Ephemeroptera: Polymitarcyidae), with description of eleven new species and a key to male imagos of the genus, Zootaxa 4300 (3), pp. 301-354 : 334-338

Campsurus indivisus Ulmer

( Figs. 123–137 , 174 )

Campsurus indivisus Ulmer, 1942: 16 (male, female); Domínguez et al., 2006: 572.

Campsurus duplicatus Spieth, 1943: 7 (male); Traver, 1947: 383; Domínguez et al., 2006: 570. SYN. NOV.

Material. ARGENTINA: 1 ♂ i from Formosa, Arroyo Torhue , 10 km S Formosa, 8.xii.1986, E Domínguez col. (IBN) [approx. S 26° 16' / W 58° 16']. BRAZIL: 7 ♂ i and 14 ♀ i from Rio Grande do Sul, Bossoroca, Barra do Angico , rio Piratinim , 27.xii.2007, AMO Pes col. ( CZNC, used in redescription, approx. S 28° 43' / W 54° 54') ; 8 ♂ i, and 1 nymph from Espírito Santo, Alegre, Cachoeira da Fumaça, rio Grande , S 20° 37' 52" / W 41° 36' 12.9", 447 m, 27.v.2011, light trap, FF Salles col. ( CZNC) ; 4 ♂ i and 3 ♀ i (sockets on sternum VIII drawn from this material) from Amazonas, São Gabriel da Cachoeira , praia em frente a cidade, lençol, 23.viii.2011, S 00° 08'13" / W 067°05'01", PV Cruz col. (IBN) ; 3 ♂ i from Amazonas, Barcelos , rio Demeni , boca do rio, 8–9.viii.2009, S 0° 25' 29" / W 62° 54' 20", pennsylvania light trap, N Hamada col. ( CZNC) ; 2 ♂ i from Amazonas, Arquipélago de Anavilhanas , 19.v.1982, JL Nessimian col. ( CZNC) ; 4 ♂ i from Amazonas, Arquipélago de Anavilhanas, Manaus , S 3° 5' – W 59° 59', 30.vii.2000, light trap, JL Nessimian col. ( CZNC) ; 38 ♂ i from Arquipélago de Anavilhanas, Manaus , 31.vii.2000, light-trap, JL Nessimian col. ( CZNC) ; 5 ♂ i from Arquipélago de Anavilhanas , flutuantes, 22.viii.1980, light trap, JL Nessimian col. ( CZNC) ; 2 ♂ i from Roraima, Caracaraí, rio Branco, Bem Querer , N 01°55' / W 61°00', 18–21/xi/2002, AMO Pes col. ( CZNC); 10 nymphs (1 male pharate subimago) from Roraima, igarape do Arraia, 20.x.2004 ( CZNC); 2 nymphs from Roraima, rio Ereu , Faz, S. Sebastião, 25.iii.2002 ( CZNC) ; 100 ♂ i from Rio de Janeiro, Rio Pirai , 15.iii.1978, SM Pereira col. ( CZNC, except 4 en IBN) ; 30 ♂ i from Roraima, Boa Vista, Rio Cauamé, N 2° 49' 11" / W 60° 40' 24", 28.ii.2003, UV light trap ( CZNC); 26 nymphs (6 mature) from Roraima, rio Cauamé , N 2° 49' 11" / W 60° 40' 24", 1.iii.2003, pedras+esponjas, N. Hamada col. ( CZNC); and 9 nymphs (2 mature) from Roraima, -I#5- Cpa, 5.xi.2006 ( CZNC).

Male imago (note Morphological Variability section, below Diagnosis). Length (mm): body, 7.5–10.0; foreleg, 3.7–4.0; fore wing, 7.0–9.8; hind wing, 3.4–4.5; cerci, 20.0–24.5. General coloration whitish yellow with gray marks ( Fig. 166 ). Head yellowish, shaded with black among ocelli ( Fig. 166 ), occiput very diffusely shaded with gray; ventrally with pair of gray marks. Antenna whitish, shaded with gray. Thorax ( Fig. 166 ). Pronotum translucent, shaded with gray mainly on anteromedian third, but paler between anterior and posterior portions, and on medial band; hump hyaline. Mesonotum yellowish, shaded with gray outward from parapsidal sutures, on PSP and area between PSP; inner and outer margins of parapsidal sutures suffused with gray. Metanotum yellowish, shaded medially with gray. Pleura and sterna pale, shaded with gray slightly on prosternum, and on meso- and metafurcasternal membranes; mesopleura with longitudinal, gray dash at middle. Legs yellowish white; fore coxa with larger subbasal and subapical gray marks; rest of fore leg whitish, shaded with purplish gray on trochanter, outer basal margin of femur, and on tibia and tarsus; each tarsite widening medially (except in males from Rio de Janeiro); middle coxa with longitudinal gray stripe, middle femur with gray spot. Wings. Membrane translucent, shaded with light purplish gray on basal half of C and Sc areas; veins translucent whitish, very slightly shaded with purplish gray on larger veins; hind wing similar in coloration to fore wing, but almost without shading. Abdomen ( Fig. 174 ) whitish, shaded with gray dorsally, except on pleural folds, median wide band on terga I–VII, submedian circular mark on terga III–VII, and very thin, median, transversal and discontinuous stripe on terga II–VI; terga VIII–IX more widely shaded except rounded sigilla and medial area near posterior margin, tergum X shaded gray medially and with posterolateral membranous extensions. Sterna pale, shaded with gray on lateral areas of sternum VIII; paraproct posteriorly projected and shaded with gray apicomedially. Genitalia ( Figs. 123–128 ): yellowish white; hind margin of sternum IX strongly concave, with short medial furrow, posterolateral round corners slightly to markedly protruding, 2- to 5-pointed microlepides present ( Fig. 128 ); pedestal bases distinctly separated in middle ( Figs. 123, 125 ), pedestals with long and apically rounded parastylus (p in Fig. 124 ), inner corner only slightly projected (ic in Fig. 124 ); penes base (bp in Fig. 125 ) large and apically membranous, with short apicodorsal extension; main lobe of penes (ml in Fig. 125 ) finger-like, slightly curved ventromedially; secondary lobe of penes (sl in Fig. 125 ) tubular and short, sometimes with tiny seta-like apical projection. Caudal filaments whitish translucent.

Female imago. Length (mm): body, 9.2–10.5; fore wing, 11.5–12.0; hind wing, 4.6–5.0; cerci, 2.8–3.5. Similar to male, except general coloration slightly darker. Thorax. Mesonotum yellowish, shaded with gray on medial line, parapsidal sutures, PSP and area between PSP; inner and outer margins of parapsidal sutures suffused with gray. Abdomen similar to male, except terga more widely shaded gray; tergum X with pale submedian spot. Sterna slightly shaded with gray, sternum VIII slightly darker laterally; paraproct whitish. Sternum VIII with pair of small submedian sockets, inner side of sockets touching each other medially ( Fig. 129 ). Sternum VIII almost completely covered with spine-like microtrichiae directed forward, except directed rearward around and in socket entrance.

Egg. Length, 285–300µm; width, 225–250µm. Yellowish, no polar cap present; small circular, otherwise amorphous, adhesive structure on convex side.

Mature nymph. Length of male (mm): body, 7.5; cerci, 5.5; caudal filament, 6.0. Length of female (mm): body, 10.0–11.0; cerci, 4.5; caudal filament, 6.5. Head ( Fig. 130 ) with frons completely covered with long setae, anterior margin almost straight, anterolateral tubercle with apex up-curved, anterior half of gena slightly protruded and with row of strong setae, posterior half of gena bare, except with oblique row of 6–8 setae before eye; inner margin of eye with two anterior setae and one posterior long seta ( Fig. 130 ). Antenna pedicel almost twice as long as scape, both dorsally covered with very long, strong setae; flagellum 1.25× length of head capsule, scattered with very short, weak setae. Mandibular tusk ( Figs. 131–133 ) flattened, exposed area 0.6× length of head capsule, apex curved inward; dorsal surface bare, except for scattered microtrichiae (visible at>400×), outer margin with few long setae, group of stout setae at base (ds in Fig. 133 ), and row of about 15 strong, spine-like setae (arrows in Fig. 133 ); inner margin with 13–15 small and blunt tubercles (t in Fig. 133 ) intercalated with short and stout setae (s in Fig.133 ); ventral surface of tusk with basal row of long setae at inner margin and few others directed medially ( Figs. 131–132 ). Maxilla with very short, subtriangular ventral gill. Thorax. Posterolateral corner of pronotum and propleura bare; metasternum completely covered with short setae. Legs ( Figs. 134–137 ). Fore legs with posterior half of coxa with short setae; trochanter bare; femur slender, ratio L/W =2.6; dorsal surface of femur ( Fig. 134 ) with submarginal group of ca. 15 long and strong setae at base of inner margin, another basal group of ca. 8 shorter setae near outer margin, and distal marginal group of medium-length rigid setae on outer margin; ventro-basal filtering setae arranged in distally open, U-shaped row ( Fig. 135 ); tibia-tarsus with margins subparallel (but slightly converging distally), dorsal surface with stout spines and long setae covering longitudinal strip widening toward base( Fig. 134 ), ventral surface with 2 rows of filtering setae ( Fig. 135 ): basal transversal W-shaped row along ventral surface and hind margin, and U-shaped longitudinal row along fore margin; apex of tibia-tarsus cleft, outer corner projected, reaching half length of tarsal claw; tarsal claw slightly curved and with three minute marginal denticles increasing in size distally ( Fig. 134 ). Middle leg ( Fig. 136 ) with coxa and trochanter with setae; dorsal surface of femur covered with many long setae along margins, and with medial row of ca. 15 long setae at basal half, ventral surface bare; tibia with anterior margin distally projected and with crown of strong spines, anterior margin basally bare, distal third densely covered with thick yellowish setae, posterior margin completely covered with very long setae; tarsus, except for absence of crown of spines, similar in setation to tibia; tarsal claw slender, more strongly curved than fore tarsal claw and with row of 16 minute denticles. Hind leg ( Fig. 137 ) similar to middle leg, except for absence of crown of spines on tibia, presence of subapical transversal band of long setae, and tarsal claw with row of 14 smaller denticles. Abdomen. Lateral margins of all segments densely covered with whitish setae. Terga III–VI with medial row of setae, posterolateral corner of tergum X with small spine. Sterna I with scattered short setae, sterna IV–VI with setae on hind margin, more numerous on V and VI, sterna VIII–IX with very few scattered long setae; paraproct well developed. Gills. Abdominal gill I bilobed, relatively short and whitish translucent, dorsal lamella almost 4× width and 2× length of ventral lamella; gills II–VII whitish translucent, except trachea blackish. Cercus 0.4× length of body, densely covered with setae dorsally and ventrally; terminal filament 0.65× length of body, with long setae decreasing in length toward apex.

Distribution ( Fig. 180 ). Brazil (Amazonas, Roraima, Espírito Santo, Rio de Janeiro, Rio Grande do Sul) and Argentina.

Diagnosis. Campsurus indivisus can be distinguished from other species of Campsurus , in the adult stage, by: 1) posterior margin of male abdominal sternum IX strongly concave with posterolateral round corners slightly to markedly protruding ( Fig. 123 ) and with short medial furrow; 2) pedestals bases distinctly separated in the middle ( Fig. 123 ), pedestals with long and apically rounded parastylus (p in Fig. 124 ), inner corner slightly projected (ic in Fig. 124 ); 3) penes base large, apically membranous and amorphous with small apicodorsal extension; main lobe of penes finger-like and slightly curved ventromedially (ml in Fig. 125 ), secondary lobe of penes tubular and short (sl in Fig. 125 ); 4) small to medium size (length of male fore wings 7–10 mm); 5) female sockets as in Fig. 129 ; 6) egg without polar cap, with amorphous structure on convex side. In the nymph: 1) anterolateral blunt tubercle at base of antenna with apex curved upwards, pedicel and scape with long strong setae ( Fig. 130 ); 2) pre-ocular group of setae on gena formed by 6–8 setae in oblique row, inner margin of eye with 3 setae ( Fig. 130 ); 3) mandibular tusks ( Figs. 131–133 ) somewhat flattened, with apex slightly curved inward, inner margin with 13–15 small blunt tubercles, outer margin with ca. 15 strong spine-like setae (mostly near the base), dorsomedial surface bare; 4) fore femur ( Figs. 134–135 ) slender (ratio L/W = 2.6), fore tibiae with subparallel margins; 5) all tarsal claws with minute denticles increasing in size distally, distributed in marginal row of 3 denticles on fore claw but 14–16 denticles in middle and hind claws.

Morphological variability. Male imagos from Arquipélago de Anavilhanas (Manaus) show some notable variations. The head is darker on the medio-longitudinal band, and stripes emerge from this band. Gray-shading is more pronounced, mostly on the abdomen (all sterna shaded laterally) and the thoracic pleura & sterna (carinae shaded).

Discussion. We here propose that C. duplicatus is a subjective junior synonym of C. indivisus , because the illustrations and descriptions given by Spieth (1943) coincide with Ulmer’s (1942) characterization of C. indivisus . The nymph of C. indivisus can be easily differentiated from other species due to the relatively scarce setae and spines on the mandibular tusks; on the outer margin, only ca. 15 spine-like setae are present, most of them near the base and only 3–4 on the apical half of the tusk. Campsurus indivisus is most closely related to C. inusitatus sp. nov. (see discussion under this species). Characters on the egg (no polar cap, amorphous structure on the convex side) and nymph (setation of head and mandibular tusk) are also present in most species nearly related to C. cuyuniensis and C. lucidus .

Figures

FIGURES 180. Distribution maps.

FIGURES 123 – 128. Campsurus indivisus, adult, SEM: 123, male terminalia, v. v.; 124, detail of pedestal, v. v. (p = pedestal, ic = inner corner); 125, detail of penes and pedestals, v. v. (bp = base of penes, g = gonopore, ml = main lobe of penes, sl = secondary lobe); 126, detail of apical portion of penes, v. v; 127, gonopores (g) at base of penes, v. v.; 128, microlepides on male sternum IX.

FIGURES 129 – 137. Campsurus indivisus. Female adult: 129, partial view of abdominal sternum VIII and detail of sockets. Nymph: 130, head, d. v.; 131, left mandibular tusk, d. v.; 132, same, inner view; 133, 134, fore leg, d. v. with detail of claw; 1 35, fore leg, v. v. (schematic, showing arcs of filtering setae); 136, middle leg with detail of claw, d. v.; 137, hind leg with detail of claw, d. v.

FIGURES 171 – 175. Male imago, general view, dorsal: 171, C. povilla sp. nov.; 172, C. lucidus; 173, C. demeni sp. nov.; 174, C. indivisus (from Alegre); 175, C. inusitatus sp. nov.

FIGURES 163 – 166. Male imago, general view, dorsal: 163, C. latipennis; 164, C. salobra; 165, C. essequibo; 166, C. nessimiani sp. nov. Abbreviations: ap = anteronotal projection, mps = medio parapsidal suture, ph = pronotal hump, psp = posteroscutal protuberances.