Asthenopus guarani, 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 : 92

Taxon classification Animalia Ephemeroptera Polymitarcyidae

Asthenopus guarani sp. n. Fig. 16 G–I, 17 E–F, 18C

Type material.

Holotype male imago (slide IBN473CM) from Argentina, Corrientes, Parque Nacional Mburucuya, Selva Misionera (sector 6), luz, 29.iii.2001, F. Navarro col.

Additional, non-type material. One reared female subimago (IBN524CM) and nymphal cuticle (IBN639CM) from Argentina, Corrientes, Laguna Brava, 27.i.1977, Poi de Neiff col. (egg in Fig. 18C extracted from this female); and 1 male imago (IBN638CM) from Uruguay, Salto, near Salto Grande, frente a Isla del Paredón, 20−21.I.1975, luz 22hs; 4 male and 10 female imagos from Brazil, São Paulo, Luiz Antonio, 10.iv.1991, C.G. Froelich col. (MZSP); 1 male and 4 female imagos from Brazil, São Paulo, Luiz Antonio, Reserva Jatai, 9.iv.1990, C.G. Froelich col. (MZSP).

Diagnosis.

Asthenopus guarani , known from all stages, can be distinguished from the other species in the genus by the following combination of characters (seven autapomorphies are detailed in Appendix 2): 1) male FW 8.0-9.0 mm (Fig. 16 G–H), female FW 16.0 mm; 2) Ratio FW/foreleg length 1.4-1.8; 3) pronotum width/length ratio: 2.15 (male), 3.1 (female); 4) male FW with 4-6 marginal intercalaries (24-26 in female), slightly shorter than the separation of main veins, HW (Fig. 16I) with 2-4 marginal intercalaries (8-9 in female); 5) male FW with 0-2 cross veins between Rs and MA basal to Rs fork (3 in female); 6) forceps relatively slender, ratio length/basal width 4.8-5.8 (Fig. 17 E–F); 7) penes tubular and slender, furrow separating penis lobe from thumb well marked; median remnant of styliger plate with lateral rounded lobes as in Fig. 17E). 8) female sternum VIII with reduced, not distinguishable female sockets, but with a long anteromedian keel; 9) eggs (Fig. 18C) ratio maximum width of egg/maximum width of PC 1.2, cap formed by 3-8 filaments, disk-like structures well separated by smooth chorion, with 2-3 small disks beneath each larger disk (Fig. 18C); 10) nymph, ratio total length of mandible/mandibular tusk length 1.4; 11) inner margin of left mandibular tusk with subbasal and submedian tubercles well separated (similar to Fig. 14C, E).

Male imago. Length (mm): body, 6.5-9.0; FW, 8.0-9.0; HW, 3.6-4.0; foreleg, 5.1-5.4; cerci, 25.4-28.0. General coloration yellowish white. Head whitish shaded with black dorsally except on hind margin and posteromedian pale mark; frons pale shaded with a pair of black submedian longitudinal lines; venter of head pale. Antennae whitish shaded with gray on scape; length (mm): scape 1.75, pedicel 1.25, flagellum 7.5. Thorax. Pronotum whitish translucent, shaded black on anterior ring and lateral margins; posterior rings shaded gray, with darker mediolongitudinal line. Meso- and metanotum yellowish white, shaded gray on scutellum; sterna pale shaded gray only on mesokatepisternum. Legs whitish shaded gray on coxae. Foreleg completely shaded gray, paler on base of tarsal segments 2-5 (Fig. 20H). Middle and hind legs shaded gray on apical half of femora and apical 2/3 of tibiae, tarsi and claws translucent. Wings (Fig. 16 G–I). Membrane of both wings hyaline, except shaded with light gray at base of costal margin in both wings and whitish on the apex of costal margin of FW; veins translucent, except Sc and R1 whitish, all veins shaded slightly gray but more diffusely toward apex. Abdomen whitish, terga uniformly shaded gray, paler laterally and anteriorly to each tergum; sterna whitish. Genitalia (Fig. 17 E–F) whitish, penes yellowish white. Cerci whitish translucent.

Female subimago. Length (mm): body, 12.5; FW, 16.0; HW, 6.5; cerci broken off and lost. General coloration orangish yellow shaded widely black. Head dorsally blackish except medial line on occiput, and anteriorly to median ocellus. Thorax. Pronotum width 2.5 mm, total length 0.8 mm; cream shaded black on thin anterior ring, with gray on posterior ring, membranes whitish. Mesothorax orangish yellow with gray markings. Wings translucent whitish, veins whitish except basal half of C, Sc and R yellowish. Abdomen uniformely shaded gray dorsally, except on pale medial line. Sternum VIII with long and thin anteromedian keel. Base of caudal filaments whitish (rest broken off and lost).

Eggs (Figs 18C). Length, 160-200 µ; width, 100-160 µ. Polar caps (max. width 130 µ) formed by 3-8 long coiled threads. The disk-like structures are circular and entire (not partitioned as other species), very well separated by smooth chorion, and when removed, a group of 2-3 very small disks are visible beneath (Fig. 18C).

Nymph (cuticle from reared female described above). Length (mm): body, 16.5 mm; cerci and terminal filament, 7.0 (both broken at apex). Antennae broken off and lost. Mouthparts. Mandibular tusks with relatively large space between the large basal tubercle and smaller subdistal tubercle, not C-shaped (similar to Fig. 14C, E, G). Legs. Foretarsal claw with a row of 26-29 denticles. Apex of hind femur with a group of 90-100 stout acute spines.

Etymology.

The name refers to one of the etnic groups inhabiting the area where the specimens were collected.

Distribution.

Argentina (Corrientes), Brazil (Sao Paulo), Uruguay (Salto).

Discussion.

This species is very distinctive, not only by the long and slender penis lobe, but also because of the presence of relatively long marginal intercalary veins (in male FW and HW). The reared female subimago is tentatively associated with the male, because of similarity in coloration and shared distributional range. Eggs extracted from this female show also some differences from the other known in the genus, mainly the larger extent of smooth chorion around the plates and the presence of small disks below the larger ones (Fig. 18C).