Asthenopodes traverae, Molineri, Carlos, Salles, Frederico F. & Peters, Janice G., 2015

Molineri, Carlos, Salles, Frederico F. & Peters, Janice G., 2015, Phylogeny and biogeography of Asthenopodinae with a revision of Asthenopus, reinstatement of Asthenopodes, and the description of the new genera Hubbardipes and Priasthenopus (Ephemeroptera, Polymitarcyidae), ZooKeys 478, pp. 45-128 : 76

Taxon classification Animalia Ephemeroptera Polymitarcyidae

Asthenopodes traverae sp. n. Figs 11 E–H, 12 C–D, 13B, D, F, 20C

Asthenopodes sp. "females from Uruguay", Traver 1956: 5.

Material.

Holotype (IBN) male and paratypes (IBN) 4 males and 22 females (slides IBN468-469CM) from ARGENTINA, Misiones, Parque Provincial Urugua-í, Arroyo Uruzú, 7−11.xii.1999, C. Molineri col.; 1 female imago (" Asthenopodes sp." Traver det.) from URUGUAY, Artigas (Uruguay 19), 9.i.1952; and 27 female adults from URUGUAY, Artigas, Sepulturas (D-3), 18.xii.1952, Carbonell col. Paratypes from Uruguay deposited in FCE-Ep.

Non-type material: 1 female (wings on slide) from BRAZIL, Sao Paulo, Jacareí, rio Paraiba do Sul, 21.xi.1987, CG Froehlich et al. cols (deposited at MZSP).

Diagnosis.

Four autapomorphies characterize this species, all are small changes in continuous characters, except the marked shortening of the median remnant of styliger plate (at the middle, since laterally a tong-like projection is present, Fig. 12C). Asthenopodes traverae sp. n. is known in the alate and egg stages, all females are subimagos even those that apparently have laid the eggs (empty females). This species can be distinguished from the other species of the genus by the following combination of characters: 1) males yellowish white, females blackish; 2) FW length male 14.0-14.5 mm, female 15.5-22.5 mm, membrane yellowish hyaline; 3) male foreleg length 0.9-1.0 times the length of FW; 4) pronotum width/length ratio: 1.3-1.9 (male), 2.0 (female); 5) 16-22 marginal intercalary veins present on the entire margin of FW (also present in HW) generally longer than distance between longitudinal veins, fused to main veins, poorly anastomosed (Fig. 11 E–H); 6) male FW with 4 to 5 cross veins between Rs and MA basal to Rs fork; 7) ratio total length/basal width of forceps 4.7-4.9 (Fig. 12 C–D); 8) median remnant of styliger plate posterolaterally expanded forming a pair of rounded projections, penes large and robust, sclerotized, curved and twisted (Fig. 12 C–D); 9) female sternum VIII with anteromedian sockets well developed, whitish surrounded by a large brownish area (Fig. 13D); 10) egg caps small, much thinner than maximum width of the egg, formed by 5-6 filaments; medium-sized and small chorionic plates present (Fig. 13B).

Male imago. Length (mm): body, 12.2-13.5; FW, 14.0-14.5; HW, 6.8-7.3; foreleg, 12.3-14.0; cerci, 35.5-38.5. General coloration yellowish white. Head shaded black dorsally almost entirely, with a pair of distinct submedian black marks anteriorly to median ocellus; occipital hind margin with pale median zone; head ventrally pale without markings. Antennae: scape and pedicel short, yellowish on venter of pedicel, both slightly shaded with gray; flagellum very thin, hyaline, similar in length to forefemur. Thorax. Pronotum translucent, shaded slightly with gray except on membranes separating anterior and posterior rings, darker laterally; pronotum width/length: 1.3-1.9. Meso- and metanotum yellowish white with gray markings mainly posteriorly but also on sutures. Thoracic pleurae and sterna yellowish white shaded gray only at base of coxae and wings. Legs. Forelegs: coxa dorsally whitish with a gray mark, ventrally yellowish; femur dorsally yellowish shaded gray on apical third, ventrally whitish; tibia whitish translucent shaded gray mainly on dorsum; tarsi translucent shaded slightly with gray; large claws, stalk with brown inner margin, rest whitish; articulations between femur-tibia and tibia-tarsus very sclerotized, brownish. Middle and hind legs yellowish, shaded with gray from half of femur to apex of leg. Wings (Fig. 11 E–H). Membrane hyaline slightly tinged with gray on costal and subcostal sectors (membrane yellowish under transmitted light); all veins light gray, lighter toward hind margin; 5 cross veins between R stem and M sector; long marginal intercalaries on hind margin of both wings. Abdomen yellowish white widely shaded with gray, some darker marks as follows: submedian short anterior dashes and sublateral oblique stripes on terga III–VIII, lateral margins of terga VIII–IX, and median line of IX–X (thinner on X). Abdominal sterna whitish except gill sclerites yellowish white. Genitalia (Fig. 12 C–D): lateral margins of sternum IX and pedestals yellowish; median remnant of styliger plate whitish with a gray strip on hind margin between the tongue-like projections ( “Ll” Fig. in Fig. 12D); pedestals well separated from each other, relatively long and becoming wider distally; forceps whitish, long and wide; base of penes well developed, subquadrate, whitish; penes strongly sclerotized, orangeish basally but yellowish distally. Cerci whitish, terminal filament reduced to 7-8 thin annuli, straight, whitish.

Female subimago. Length (mm): body, 9.5-19.0; forewing, 15.5-22.5; hind wing, 7.5-11.5; cerci 3.5-4.0. General coloration dark brown shaded widely with black. Head black dorsally, yellowish white ventrally except on remnants of tusks, brownish. Antennae dark brownish except apical half of flagellum whitish. Thorax. Sclerites dark brown, membranes shaded black. Pronotum width/length: 2. Legs brownish except membranous portions, whitish. Wings (Fig. 11 G–H) with yellowish brown membranes and veins, veins C and Sc darker. Abdomen. Terga dark brown completely shaded black; sterna paler, brownish laterally, yellowish medially, with two or more pairs of small pale dots; sternum VIII with two small anteromedian sockets (Fig. 13D). Caudal filaments brownish, terminal filament shorter than tergum VIII, cerci 0.3-0.4 times the length of the abdomen (0.2 the length of FW).

Eggs (Fig. 13B). Length, 305-355 µ; width, 195-225 µ. Two small polar caps (maximum width, 70-82.5 µ) formed by 5-6 long coiled threads. Chorionic surface smooth with regularly spaced chorionic plates. Chorionic plates ( “disk-like” structures) relatively small and rounded, with irregular margins. Smaller plates, irregular in form scattered between the larger ones.

Etymology.

The species is dedicated to the great mayfly specialist Jay R Traver, who visited Uruguay and worked with Mr. C. S. Carbonell’s collections at the "Museo de la República” recognizing the females of this species as distinct from Asthenopus picteti (also unknown at that time).

Distribution.

Parana biogeographic subregion in Argentina, Uruguay and Brazil.

Biological remarks.

Females subimagos were collected (in Misiones Province) while swarming in compact groups at about 3 m above water in pool areas around sunset. The same behavior was reported by Traver (1956) for the Uruguayan females. Males were caught at light traps during the first hours of dark, so the male flight is unknown.

Discussion.

Traver (1956) described females of Asthenopodes traverae as distinct from Asthenopus picteti in spite of the fact that the female of that species was also unknown at that time. Nevertheless Traver realized that they differ from Asthenopus picteti males in color and size, and left them unnamed. With the collection of new material from both species (and sexes) in Misiones (Argentina), it became evident that they constitute a new species. Asthenopodes traverae females can be distinguished from Asthenopus picteti females by their black general coloration, somewhat slender forewings, femora and cerci widely shaded with black, and enlarged abdominal gill sclerites (remnants of nymphal gill muscles insertions), for other differences see discussion under Asthenopus picteti . Very similar in aspect but much smaller are the females of Asthenopodes chumuco , the allopatric sister species of Asthenopodes traverae .