Tapsatella albocastanea Rubio, Stolar & Nadal, 2020

Rubio, Gonzalo D., Stolar, Cristian E., Nadal, María F. & Baigorria, Julián E., 2020, The jumping spider Tapsatella albocastanea, a new genus and species from Argentina (Araneae: Salticidae: Freyina), Peckhamia 203 (1), pp. 1-9 : 4

Tapsatella albocastanea Rubio, Stolar & Nadal , sp. nov.

( Figures 1-4 )

Material examined. Types: Male holotype (IBSI-Ara 0843; tiss.s. 0843) from Argentina, Chaco: Capitán Solari , Parque Nacional Chaco (S26.807°, W59.608°), habitat “quebrachal-ralera” (Dry Chaco savanna), 24 October 2016, G.D. Rubio & E.I. Meza-Torres coll. Female paratype (IBSI-Ara 0842; tiss.s. 0842) same data as holotype . Other material: 1 male ( CNNE 9212) from Chaco: Presidencia de la Plaza, Estancia Los Alisos (S27.086°, W59.764°), habitat grassland, 17 October 2007, Avalos et al. coll.

Etymology. The species group name "albocastanea" is a Latin compound adjective that means "white and brown", due to the color pattern of these specimens.

Diagnosis. As for the genus.

Description. Male (holotype) illustrated in Figures 1 A-B, 2A-C, 3A-G and 4A-C. Total length: 5.44. Carapace length: 2.44; width: 1.57. Carapace dark brown, cephalic region uniform with some scattered white setae (conspicuous in life), eyes (except AME) bordered by blackish scales, thoracic slope with a lighter longitudinal middle stripe (with white hairs in life), wide white marginal bands continued from the clypeus. Chelicerae dark mahogany brown, with one promarginal and one retromarginal tooth. Sternum light brown, with abundant white translucent hairs. First pair of legs stout, hairy, dark brown (darker in life), rest of the legs light brown. Abdomen length: 3.00, width: 1.60, coloration pale brown (covered with whitish hairs in life), with two dark brown longitudinal bands on the dorsum, each with conspicuous darker edges. Dorsal scutum weakly sclerotized, hard to see, barely darker on the heart region. Palp: femur stout, tibia with a conspicuous ventral prong of RTA (vRTA) wide base, narrower towards the apex, triangular-shaped. Tegulum clearly divided, with the border between TBD and TDD transverse in ventral view. TDD with pRL wide, short and angled edges. Embolus almost straight, wellsclerotized with conspicuous base, not bent at the EB. Numerous spicules (Spc), or tiny spike-like structures following Edwards (2015) near the EB ( Figures 3 F-G). TBD with a short and curved visible section of the S.

Female (paratype) illustrated in Figures 1 C-E, 2D-F, 3H-J, 4D-E. Total length: 7.10. Carapace length: 2.90, width: 1.82. Carapace dark brown with two darker longitudinal stripes (in life these stand out on a cover of white hairs), eyes on a blackish brown broadband, thoracic slope with a lighter longitudinal middle band (with white hairs in life, continue throughout the carapace), wide white marginal bands continued from the clypeus. Chelicerae as in male. Sternum as in male. First pair of legs slightly stronger than the rest, brown, hairy. Abdomen length: 4.20, width: 2.40, with two blackish brown longitudinal bands on the dorsum (in life they clear up on the heart region). Epigyne: epigynal plate conspicuous, longer than wider, with two anterolateral circular CO; CD with two different stretches, one anterior (thicker) and the other posterior (thinner) connecting to a small spherical spermatheca, FD anterior to spermatheca.

Natural history. Considering that all specimens were found on grasses in "quebrachal-ralera" ( Schinopsis balansae ), the species T. albocastanea sp. nov. may be typical of this habitat.

Distribution. Only known from Chaco Province in northeastern Argentina. Remarks. The specimens of the species described here, Tapsatella albocastanea sp. nov., have an appearance similar to W. denticulata and W. punctata , with a striped dorsal pattern. The femur is stout and arched dorsally as in other Wedoquella , although also similar to Pachomius Peckham & Peckham, 1896 or Phiale . The dorsal broadly angulate prong of the RTA (dRTA) and TDD does not have the oblique appearance of Trydarssus Galiano, 1995 as do Wedoquella . The female has small and spherical spermathecae as in W. denticulata and W. punctata , somewhat similar to some Phiale and to Trydarssus nobilitatus (Nicolet, 1849) , but the posterior edge of the epigyne is not as bilobed as in Trydarssus . On the other hand, the embolus with spicules near the base is similar to Pachomius but this has not been important to the delimitation of genera since Edwards (2015) observed a range of variation in this structure so great that the inclusion of otherwise similar species that completely lack, or do not lack, spicules does not seem unreasonable. The placement of T. albocastanea sp. nov. in an existing genus is problematic, and although we think that Wedoquella is the genus that shares the most characteristics with Tapsatella , we also think that it is more stable to separate the two genera.

Figures

Figure 1. Habitus in nature of Tapsatella albocastanea sp. nov. from "quebrachal-ralera" in Chaco National Park, Argentina. A-B, Male (holotype). C–E, Female (paratype).

Figure 2. Preserved specimens of Tapsatella albocastanea sp. nov. A–C, Dorsal, lateral and frontal views of male (holotype). D–F, Dorsal, lateral and frontal views of female (paratype).

Figure 3. Sexual structures of Tapsatella albocastanea sp. nov. A–G, Male palp (holotype). A, Ventral view. B, Retrolateral view. C, Detail of RTA. D-E, Copulatory bulb. F-G, details of Spc (arrows) in ventral and dorsal views. H–J, Female epigyne (paratype). H, Ventral view. I, Cleared ventral view. J, Cleared dorsal view.

Figure 4. Sexual structures of Tapsatella albocastanea sp. nov., drawings. A–C, Male palp (holotype). A-B, Ventral views. C, Retrolateral view. D-E, Female epigyne (paratype). D, Cleared ventral view. E, Cleared dorsal view