Birabenia Mello-Leitão

Piacentini, Luis N. & Laborda, Alvaro, 2013, The South American wolf spider genus Birabenia Mello-Leitão, 1941 (Araneae: Lycosidae: Lycosinae), Zootaxa 3716 (1), pp. 39-52 : 40-42

Birabenia Mello-Leitão

Diagnosis. The representatives of Birabenia can be distinguished from other genera of Lycosinae by the relatively short legs ( Fig. 1 d) and the deep anterior epigynal pockets. ( Fig. 5 b) These characters are also present in Trochosa C. L. Koch, 1847 from which it can be differentiated by having more than seven macrosetae at the tip of cymbium ( Fig. 3 f), a shorter furrow ( Fig. 3 b) on the prolateral side of the tegulum on the male bulb, the presence of only one pair of short apicoventral spines on female tibia I, or none and four cheliceral teeth on the female retromargin ( Fig. 4 e). Both males and females lack the typical dark stripes on the anterior part of the median light band of the carapace, characteristic of Trochosa (Dondale & Redner 1990) .

Remarks. We propose diagnostic characters to distinguish B. birabenae from Trochosa ruricola (De Geer) , the type species of genus.

Description. Medium sized wolf spiders (males 4.92–8.91, females 7.05–12.64), carapace brown with a light median band and paler marginal bands, radial pattern indistinct. Sternum uniformly coloured, pale. Chelicerae with four retromarginal teeth, except in males of B. vittata , which have three teeth ( Fig. 4 e). Abdomen brownish yellow with two dark olive gray lateral bands; venter brownish yellow with two middle dark lines ( Fig. 1 ). Leg formula 4123. Femur I with one prolateral apical spine, and three pairs of ventral spines in males and none in females. Scopulae on legs I and II from ventral distal half of metatarsi ( Figs 4 c, 9c), on legs III and IV present ventrally in two lines on prolateral and retrolateral side of the tarsi, and spinules on ventral side ( Fig. 4 d).

Palp with tibia longer than wide ( Fig. 2 f), with a file on distal tibia ( Fig. 3 e), facing a crest (scraper) on the proximal tarsus ( Fig. 3 g). Cymbium with distal macrosetae ( Fig. 3 f); tegulum large occupying most of ventral side of bulb ( Fig. 2 b); median apophysis transversal, triangular in shape, with a distal ventral process ( Figs 2 b–e, 3b–d); embolus C-shaped arising on prolateral margin of palea, moderately long, slender, concealed, in part, by median apophysis; terminal apophysis slightly curved apicad ( Figs 2 a–b, 3b); subterminal apophysis parallel to the embolus ( Fig. 8 e).

Epigyne with inverted T-shaped median septum set in shallow atrium with two anterior pockets ( Figs 4 a, 5a); copulatory openings located on or at lateral margins of median septum ( Fig. 4 b). Spermathecae with short stalk ( Figs 4 b, 5b).

Composition. Two species B. birabenae and B. vittata .

Distribution. North-western and central Argentina (Jujuy, Salta, Tucumán, La Rioja, Mendoza, San Luis, Córdoba, Santa Fe, Entre Ríos and Buenos Aires Provinces) and southern Uruguay (Canelones, Maldonado and Rocha Departments) ( Fig. 11 ).

Figures

FIGURE 1. Birabenia birabenae Mello-Leitão, habitus. a – c female (MACN-Ar 28971); d – f male (MACN-Ar 27521); a, d dorsal; b, e lateral; c, f ventral. Scale bars, a – c 2.00 mm, d – f 5.00 mm.

FIGURE 2. Birabenia birabenae Mello-Leitão, male genitalia (MACN-Ar 27521), a – e bulb, a prolateral; b ventral; c retrolateral; d dorsal; e apical; f pedipalp, general view. Scale bars, a – e 0.20 mm, f 0.50 mm. Abbreviations: C conductor, E embolus, MA median apophysis, PA palea, ST sub tegulum, T tegulum, TA terminal apophysis.

FIGURE 3. SEM images of Birabenia birabenae Mello-Leitão, male genitalia (MACN-Ar 27521). a Left bulb, prolateral; b ventral; c retrolateral; d apical; e retrolateral view of the tibial apical part; f apical part of cymbium, ventral view; g distal part of cymbium, retroventral view. Scale bars, a – d 0.20 mm, e 0.05 mm, g 0.50 mm. Abbreviations: C conductor, E embolus, MA median apophysis, PA palea, S scraper, ST sub tegulum, T tegulum, TA terminal apophysis, TF tegular furrow.

FIGURE 4. Birabenia birabenae Mello-Leitão, female genitalia (MACN-Ar 28971), a epigyne ventral view, b vulva dorsal view, c metatarsus and tarsus of leg I ventral, d metatarsus and tarsus of leg IV ventral, e endites ventral. Scale bars, a 0.20 mm, b 0.10 mm, c – e 1.00 mm. Abbreviations: AP anterior pockets, FD fertilization ducts, HS head of spermatheca, MS median septum, Sc scopulae, Sp spinules, SS stalk of spermatheca.

FIGURE 5. SEM images of Birabenia birabenae Mello-Leitão, fe male genitalia (MACN-Ar 28971), a epigyne ventral view, b vulva dorsal view, upper right corner in b, detail of the head of spermatheca pore, Upper left corner in b, lateral view of the left spermatheca. Scale bars, a, b 0.20 mm. Abbreviations: AP anterior pockets, CO copulatory opening, FD fertilization ducts, HS head of spermatheca, MS median septum, SS stalk of spermatheca.

FIGURE 8. SEM images of Birabenia vittata (Mello-Leitão), male genitalia (FCE- 1161), a Left bulb, prolateral; b ventral; c retrolateral; d apical; e detail of the terminal part of the bulb in apical view. Scale bars, a 0.20 mm, a – d 0.20 mm, e 0.10 mm. Abbreviations: C conductor, E embolus, MA median apophysis, PA palea, StA subterminal apophysis, ST sub tegulum, T tegulum, TA terminal apophysis.

FIGURE 11. Records of Birabenia Mello-Leitão. Numbers in the circle are the type locality of each type: 1 B. birabenae and Lycosasanogastensis; 2 paralectotype of B. birabenae; 3 Birabenia taeniata; 4 Alopecosa murina; 5 Gnatholycosa. vittata. In case where location data in the label gave only the province, the point is located in the centre of the province and marked with an asterisk.