Asthenopodes chumuco, 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 : 76-79

Taxon classification Animalia Ephemeroptera Polymitarcyidae

Asthenopodes chumuco sp. n. Figs 4B, F, 9, 10, 11 I–L, 12 E–F, 13C, E, 20B

Asthenopodes sp? Traver 1950: 611.

Asthenopus picteti Domínguez et al. 2006: 562.

Type material.

Holotype and 3 paratypes male imagos from Brazil, Amazonas, Barcelos, rio Demene, ´boca´barco, S 0°25'28.7" - W 62°54'20", 8−9.viii.2009, Pennsylvania. Holotype and 1 paratype in INPA, 2 paratypes in IBN.

Additional material. 3 male slides (CUIC) from British Guiana, Bartica District, Kartabo, 20.iv.1919, C.U. Expedition col. Five female imagos (1 in CZNC, 2 in IBN, IBN533CM, 2 in MUSENUV) from Colombia, Amazonas, Puerto Nariño, Loreto Yacu, S 3°44'26" − W 70°27'19", 5.ii.1999, luz 18−20 h, M. C. Zúñiga, E. Domínguez and C. Molineri cols.

Diagnosis.

Asthenopodes chumuco known from all the stages presents seven autapomorphies, all of them are changes in continuous characters (Appendix 2). This species can be distinguished from the other species of the genus by the following combination of characters: 1) general coloration yellowish white in male, dark brown in female; 2) male FW 7.0-9.0 mm, female FW 12.2-14.8 mm; 3) male, ratio FW/foreleg length 1.4-1.6; 4) pronotum width/length male 1.3-1.4, female 2.0-2.1; 5) 7-14 marginal intercalary veins present on the entire margin of FW (Fig. 11I, K), HW (Fig. 11J, L) with 3-7 marginal intercalary veins, generally longer than distance between longitudinal veins, fused to main veins, poorly to heavily anastomosed; 6) male FW (Fig. 11I) with 3-4 cross veins between Rs and MA basal to Rs fork; 7) ratio total length/basal width of forceps 7.8-9.5 (twisted CUIC slide 6.3-6.7) (Fig. 12E); 8) male median remnant of styliger plate subrectangular, slightly convex (not expanded forming a pair of rounded lateral projections), penes long and slender, acute distally (Fig. 12 E–F), rectangular pedestals strongly enlarged, ½ the length of forceps; 9) female sternum VIII, with small reduced anteromedian female sockets at the base of a median keel; 10) egg caps small, much thinner than maximum width of the egg, formed by 14-16 filaments; large and small chorionic plates present (Fig. 13C).

Male imago. Length (mm): body, 7.3-8.0; forewing, 7.0-8.8; hind wing, 3.7-4.3; foreleg, 5.0-5.8; cerci, 20.0-23.0. General coloration yellowish white. Head shaded gray dorsally almost entirely, frons with black dot at base of antenna, with medial line and irregular black marks; occipital region with pale median zone; head ventrally pale without markings. Antennae: scape and pedicel short, subequal in length, whitish shaded with purplish; flagellum very thin, hyaline. Thorax. Pronotum whitish with anterior and posterior portion subequal in size, shaded gray in a transverse band between both portions, posterior portion black along hind and lateral margins; pronotum width/length: 1.2-1.3. Mesonotum yellowish white shaded with gray on posterior half of medial line, on area between posterolateral protuberances and on anterior margin of these structures. Metanotum yellowish slighlty shaded with gray medially. Thoracic pleurae and sterna yellowish white shaded gray dorsally and anteriorly to mid coxa. Legs. Forelegs: whitish completely shaded with gray; large claws, apically expanded (Fig. 13E). Middle and hind legs yellowish white, shaded with gray on coxae. Wings (Fig. 11 I–J). Membrane hyaline shaded with gray on basal 1/3 of costal and subcostal sectors; all veins translucent, except costal cross veins grayish; 3-4 cross veins between R stem and M sector; long marginal intercalaries on hind margin of both wings. Abdomen whitish shaded with gray on terga, mainly on lateral margin, submedian black dot on terga III–VIII. Abdominal sterna pale. Genitalia (Fig. 12 E–F): yellowish white, except for penis apically yellowish; pedestals well separated from each other, very long, ½ length of forceps; median remnant of styliger plate with slightly convex hind margin; base of penis rounded, projecting posterolaterally, lobe of penis long and sclerotized, curved ventromedially, constricted on median length, gonopore well developed. Cerci whitish; terminal filament reduced to 5-7 thin annuli, straight, whitish.

Note: Cornell male (slides, male imago). Length (mm): body missing; FW, 9.0; HW, 4.5. FW with 11 long marginal intercalary veins; 3 cross veins between R and M basad to R stem; IMP fused basally to MP1 or free; MP2 fused to IMP. HW with 6 long intercalary veins on hind margin. Genitalia: penes robust, twisted; median remnant of styliger plate without posterolateral projections; forceps long and slender, ratio length/basal width: 6.3-6.7.

Female imago. Length: body, 7.2 (shrunken, empty)-12.3; FW, 12.2-14.8; HW, 5.3-6.0; cerci, 1.2-1.3. General coloration dark brown. Head dorsally black except on clypeus, whitish with a pair of lateral brownish bands, ventraly much paler brownish white. Thorax brownish with blackish membranes and carinae. Pronotum with a pair of distinct black marks submedially; width/length ratio: 2. Legs pale, brownish white. Wings (Fig. 11 K–L) with hyaline membrane, slightly whitish translucent; veins whitish tinged with brownish basally; 2 to 4 crossveins between M and R, basally to R stem; MP2 joined basally to IMP; marginal intercalaries relatively numerous and long, anastomosed. Abdomen. Terga brownish slightly paler on median band and pleural folds, sterna much paler brownish white. Cerci basally brownish turning whitish distally; very reduced in size, less than 0.1 the length of FW.

Eggs. Length 210-240 µ, width 180-200 µ. Subovate, yellowish, with two small whitish polar caps (maximum width, 75-85 µ), polar caps much thinner than the egg and formed by 14-16 threads. Under SEM the larger disk-like chorionic structures are surrounded by many smaller ones, which at their time are surrounded by smooth chorion (Fig. 13C).

Nymphs. Length (mm): body, 7.8; cerci, 2.0-2.3; terminal filament, 3.1. General coloration yellowish light gray (Fig. 4B, F). Head with a black band between lateral ocelli and fine netting pattern on occiput (Fig. 4F). Antennae: scape bare, slightly longer than pedicel, pedicel with many dorsal setae, flagellum bare with numerous annuli increasing in length distally. Thorax. Pronotum shaded black on sublateral area of anterior ring and laterally on posterior ring. Meso- and metanotum shaded widely with gray, with dark gray wingbuds, developing veins paler. Legs (Fig. 10 A–D). Coxae and trochanters of mid and hind legs slightly shaded with gray, remainder of legs yellowish-white; foretarsal claw with double parallel rows of 15 and 12 denticles each (Fig. 10B). Abdomen. Terga more or less uniformly shaded brownish-gray, except on pale transverse dashes laterally, thin medial line on tergum I–IX becoming wider posteriorly and pale with subcircular submedian sigilla; sterna yellowish. Gill I whitish, gills II–VII purplish gray, ventral portion paler than dorsal portion. Caudal filaments yellowish.

Etymology.

“Chumuco” is one of the common names applied to river cormorans in some South American countries. The penis lobe of this new species resembles the neck and head of that bird.

Distribution.

Brazil (Amazonas, Espírito Santo), Colombia (Amazonas), Guyana.

Discussion.

The male imago of this species has been known since Traver (1950) found a group of slides containing some body parts of a missing specimen. She stated that it was surely not the type species of Asthenopodes mainly because its smaller size. Domínguez et al. 2006 (p. 562) treated this specimen in Asthenopus picteti , extending the distribution of this last species to British Guiana. With the discovery of new specimens (male and female adults) we gathered more morphological information and realized that a new species must be described. One of the results is that Asthenopus picteti is no longer considered to be in British Guiana. The Colombian females described here as Asthenopodes chumuco are associated with the males, because of the egg morphology, compared with those extracted from a pharate female from São Mateus. Adults show the smallest size of the genus, further differing from the other two species in many morphological aspects. The females are similar to Asthenopus picteti in coloration of hind femur and abdomen but wing venation and sockets on sternum VIII are different, also the female cerci of Asthenopodes chumuco are much less developed. The eggs are similar to those of Asthenopodes traverae , because of the small polar caps, nevertheless Asthenopodes chumuco presents much more threads forming each cap (between 14 and 16, but each thread is relatively very thin).