Abaycosa, Laborda & Bidegaray-Batista & Simó & Brescovit & Beloso & Piacentini, 2022

Laborda, Alvaro, Bidegaray-Batista, Leticia, Simo, Miguel, Brescovit, Antonio Domingos, Beloso, Carolina & Piacentini, Luis Norberto, 2022, Abaycosa a new genus of South American wolf spiders (Lycosidae: Allocosinae), Arthropod Systematics & amp; Phylogeny 80, pp. 59-74 : 59

3.2.1. Abaycosa gen. nov.

Type species.

Pardosa nanica Mello-Leitão, 1941.

Etymology.

The generic name derived from the combination of “Abáy”, which means spider in the language of the Chaná, an indigenous group native to the basins of the Paraná and Uruguay rivers. This language is considered critically endangered by the United Nations Educational, Scientific and Cultural Organization (UNESCO) and “cosa” a common ending of lycosids genera.

Diagnosis.

Males of Abaycosa can be distinguished by the presence of only one distal macrosetae on the tip of the cymbium, short and curved ventrally (Fig. 2 ). Males can also be separated from the remaining South American Allocosinae by the palpal tibia, which is almost as long as wide (Fig. 2 ), resembling North American representatives of Allocosa . Males of Abaycosa differ from males of North American Allocosa by having a patch of flat setae on the dorsal tip of the cymbium (Fig. 2 ). Females of Abaycosa can be distinguished by the ventral position of the vulval chamber and by the short and stout stalk of the spermathecae (Fig. 3C, D ).

Description.

Small sized wolf spiders (males 3.72-4.50, females 3.99-6.38), carapace dark brown with a light brown median band. Sternum variable in coloration from black to brownish yellow. Chelicerae dark brown with three retromarginal teeth. Abdomen light brown with two dark brown lateral bands and a brown lanceolate mark in the cardiac area with a dark brown outline; venter brownish yellow, usually with two middle dark lines (Figs 4 , 5 ). Legs brown with dark annulations, proximal articles darker than distal, without scopula, leg formula 4123 or 4132. Palp of male with tibia long as wide (Figs 2 ; 6G-I ; 7G-I ). Cymbium with only one distal macrosetae and flat setae on the tip (Fig. 2C ); tegulum large occupying most of ventral side of bulb (Fig. 3E, H ). Sierwald conductor long and triangular (Fig. 6C ); median apophysis transversal, composed by an apical arm, pointed ventrally and a basal projection that could be curved apically in A. nanica (Fig. 3E, F ) or ventrally in A. paraguensis (Fig. 3G, H ). Embolous C-shaped, not visible on ventral view; distal part of the bulb with a terminal apophysis beaklike, pointing retrolaterally in A. nanica (Fig. 6F ) or basally in A. paraguensis (Fig. 7F ), and a projection on the retrolateral side, hooked in A. nanica (Fig. 6C ) and straight in A. paraguensis (Fig. 7F ). Epigynal plate without atria, with two parallel furrows in A. nanica (Figs 3A ; 8A ) that are absent in A. paraguensis (Figs 3B ; 9A ). Vulva composed of a rounded vulval chamber and stout spermathecae, with heads of about the same size as the stalk and base (Fig. 3C, D ).

Figures

Figure 2. Abaycosa nanica (Mello-Leitao), expanded male genitalia (MACN-Ar 41946). A prolateral view. B anterior view. C retrolateral view; detail of the patch of flat setae on the dorsal tip of the cymbium and apical macrosetae. E embolus, MA median apophysis, TA terminal apophysis, TArp retrolateral projection of the terminal apophysis, MH median hematodocha, DH distal hematodocha, BH basal hematodocha, FS flat setae, AM apical macrosetae. Scale bar, 0.10 mm.

Figure 3. SEM micrographs of genitalia. A, C, E, F: Abaycosa nanica (Mello-Leitao). B, D, G, H: Abaycosa paraguensis (Gertsch & Wallace). A, B: Epigyne, ventral view, in top right corner detail of the posterior margin. C, D: Vulva, dorsal view. E, H: Male bulb ventral view. F, G: Male bulb ventral view, detail of the median apophysis. Abbreviations: FD fertilization ducts, HS head of spermatheca, MA median apophysis, PA palea, T tegulum, TA terminal apophysis, VC vulval chamber. Scale bars, A, B, D, E, H 0.10 mm, C 0.05 mm.

Figure 4. Live specimens. Abaycosa nanica (Mello-Leitao). A: male, B: female with eggsac. Abaycosa paraguensis (Gertsch & Wallace). C: male, D: female.

Figure 5. Habitus. A-D: Abaycosa nanica (Mello-Leitao). E-H Abaycosa paraguensis (Gertsch & Wallace). A, E male dorsal view. B, F male ventral view. C, G female dorsal view. D, H female ventral view.

Figure 6. Abaycosa nanica (Mello-Leitao), male genitalia, A-F bulb (MACN-Ar 41946), A prolateral; B ventral; C retrolateral; D dorsal; E apical; F detail of the TA and MA disposition; G-I pedipalp, G prolateral; H ventral; I retrolateral. Abbreviations: C Sierwald conductor, MA median apophysis, PA palea, ST sub tegulum, T tegulum, TA terminal apophysis, TArp retrolateral projection of the terminal apophysis. Scale bars, A-F 0.10 mm, G-I 0.20 mm.

Figure 7. Abaycosa paraguensis (Gertsch & Wallace), male genitalia (FCE-Ar 7903), A-F bulb, A prolateral; B ventral; C retrolateral; D dorsal; E apical; F detail of the TA and MA disposition; G-I pedipalp, G prolateral; H ventral; I retrolateral. Abbreviations: C Sierwald conductor, MA median apophysis, PA palea, ST sub tegulum, T tegulum, TA terminal apophysis, TArp retrolateral projection of the terminal apophysis. Scale bars, A-F 0.10 mm, G-I 0.20 mm.

Figure 8. Abaycosa nanica (Mello-Leitao), female genitalia (MACN-Ar 35265). A epigyne ventral view, B vulva dorsal view. Abbreviations: CO copulatory opening, FD fertilization ducts, HS head of spermatheca, VC, vulval chamber. Scale bar, 0.10 mm.

Figure 9. Abaycosa paraguensis (Gertsch & Wallace), female genitalia (FCE-Ar 2744), A epigyne ventral view, B vulva dorsal view. Abbreviations: CO copulatory opening, FD fertilization ducts, HS head of spermatheca, VC, vulval chamber. Scale bar, 0.10 mm.