Loxosceles surca Gertsch, 1967

Figs 1B–D, 8A, 9B, 10

Loxosceles surca Gertsch, 1967: 157, pl. 8, figs 4, 6, 12

(female holotype from Peru, Lima, Surco, Rimac Valley, 11.8849 S, 76.4411 W, 2000 m a.s.l., 9 Oct. 1963, A. Herrer and P. Wygodzinsky leg., deposited in AMNH, not examined). — Taucare-Ríos 2011: 45, figs 1, 3. — World Spider Catalog 2017.

Note

Males and females were collected next to each other in at least three different localities.

Diagnosis

Loxosceles surca could be confused in Chile only with the sympatric L. laeta. It is distinguished from L. laeta by the anterior border of the carapace very hirsute, the male palp with tibia narrowed medially, with a dorsal concavity, and five times longer than the cymbium (Fig. 1B–C). The female internal genitalia are very similar to those of L. laeta, but can be distinguished by the almost absent transverse enlargement at the base of the tubular receptacles (Fig. 8A).

Material examined

CHILE. I Región de Tarapacá: Tamarugal, 1 ♀, 10 imms, Huara, Chusmiza, 19.68333 S, 69.18333 W, 3–250 m a.s.l., 10 Nov. 1992, L.E. Peña leg. (AMNH). – XV Región de Arica y Parinacota: Arica, 3 ♀♀, Arica, San Miguel de Azapa, 18.53533 S, 70.14983 W, 342 m a.s.l., 12 Jul. 2012, A.D. Brescovit, A.J. Santos and A. Taucare-Ríos leg. (IBSP 167059); 1 ♀, Playa Corazones, next to the Cuevas de Anzotas, 18.5482 S, 70.3307 W, 23 m a.s.l., 12 Jul. 2012, A.D. Brescovit, A.J. Santos and A. Taucare-Ríos leg. (IBSP 167061); Parinacota, 1 ♂, 3 ♀♀, Putre, Chapiquiña, 18.39472 S, 69.53694 W, 12 Nov. 1983 (AMNH); 2 ♀♀, 2 km S of Zapahuira, 18.33333 S, 69.56667 W, 3400 m a.s.l., 3 Feb. 1994, N.I. Platnick et al. leg. (AMNH); 1 ♂, 1 imm., 24 km S of Zapahuira, 18.41667 S, 69.51667 W, 3640 m a.s.l., 3 Feb. 1997, N.I. Platnick et al. leg. (AMNH); 1 ♂, 1 imm., ditto, 3 Feb. 1998 (AMNH); 1 ♀, 6 km S of Zapahuira, 18.35 S, 69.56667 W, 3420 m a.s.l., 3 Feb. 1996, N.I. Platnick et al. leg. (AMNH); 1 ♀, 9 km S of Zapahuira, 18.35 S, 69.53333 W, 3620 m a.s.l., 5 Feb. 1994, N.I. Platnick et al. leg. (AMNH).

Description

Male (Zapahuira, Putre, Parinacota, Chile, AMNH)

Carapace yellowish, with the darker, violin-shaped median band typical of Loxosceles (Taucare-Ríos 2011: fig. 3). Endites and labium yellow. Sternum yellowish. Legs yellow with tibia, metatarsus and tarsus brown. Palp red brown, with distal articles reddish brown. Opisthosoma grey, with inconspicuous cardiac area. Total length 9.8. Caparace 3.8 long, 4.4 wide. Clypeus 0.55 high, with border hirsute. Eye diameters: ALE 0.2, PME 0.24, PLE 0.22. Sternum 2.3 long, 1.9 wide. Leg I: femur 6.0, patella 1.5, tibia 6.5, metatarsus 6.9, tarsus 2.2, total 23.1. II: 6.8, 1.6, 7.1, 7.7, 2.0, 25.2. III: 6.2, 1.6, 5.6, 6.8, 1.7, 21.9. IV: 6.9, 1.6, 7.0, 8.2, 2.0, 25.7. Tibiae sinuous, with ventral erect setae (Fig. 9B). Leg formula 4213. Palpal femur 5.2 long, 0.5 wide. Palpal tibia 2.8 long, 0.6 wide. Palp with cymbium as long the tegular base, and a long, slender and curved embolus (Fig. 1C).

Female

Described by Gertsch (1967). Clypeus as in male. Palp tarsus 1.5 long, narrow. Spermathecae with tubular receptacle straight, with sclerotized base (Fig. 8A).

Variation

Male (n = 3): Total length 8.0–10.0, carapace 4.1–4.4 long, femur I 5.6–6.8 long. Palpal tibia 2.8–3.0 long, 0.5–0.6 wide. Female (n = 8): total length 10.0–12.4, carapace 4.8–5.4 long, femur I 5.2–5.6 long. Palpal tarsus 1.4–1.6 long.

Distribution

Known only from northern Chile, in Tarapacá and Arica y Parinacota Regions (Fig. 10) and from Peru: Santiago de Surco and Chosica (Gertsch 1967).