Eremocosta bajaensis

Eremocosta bajaensis (Muma 1986)

Figs. 1A, 2A–D, 3A, 4A, 5A

Eremorhax bajaensis Muma 1986: 4 –5, figs. 8–12.

Eremopus bajaensis (Muma 1987): Muma 1989: 5.

Eremocosta bajaensis (Muma 1986): Harvey 2002: 451.

Type material. Male holotype from Baja California Norte, México, 2 miles east of Ranch San Salvador along road to Valle Trinidad from Ensenada; 21 June 1973; coll. S.C. Williams & K.B. Blair, SCW # 314(4) (CAS). Female allotype from 10.2 km north of Santa Maria, Baja California, México (CAS). Examined male holotype but was unable to examine female allotype.

Other specimens examined. Males (11). MÉXICO: Baja California Norte, 2 August 2002, coll. Rcho [sic] & Enriques (2 males: IBUNAM no number); USA: California, Riverside County, Santa Rosa Mountains, Highway 74, 1 mile W Pinyon Pines [fire station], N 33.58947°, W 116.47021°, 4000 m elev., 19 July 2005, coll. Wendell Icenogle, one male (collected near a female) on highway in car headlights at 01:30 hr (DMNS ZA.36272); USA: California, San Diego County, Alpine at home, N 32.83505°, W 116.76641°, 579 m elev., 3 July 2001, coll. D. Stokes (DMNS ZA.15433); USA: California, San Diego County, Rancho Jamul Ecological Reserve, N 32.683°, W 116.81836°, 249 m elev., 21 July 2005, coll. Dustin A. Woods, pitfall trap (DMNS ZA.16321); USA: California, San Diego County, Hollenbeck Canyon Wildlife Area, N 32.728°, W 116.815°, 524 m elev., July 2003, coll. USGS, pitfall trap (DMNS ZA.16323); USA: California, San Diego County, Rancho Jamul, N 32.683°, W 116.81836°, 249 m elev., July 2007, coll. USGS (RAJ), pitfall trap (DMNS ZA.19091); USA: California, San Diego County, San Diego Wild Animal Park [San Diego Zoo Safari Park], N 33.08983°, W 116.98668°, 201 m elev., 9–13 August 2010, coll. USGS, pitfall trap (DMNS ZA.33088); USA: California, San Diego County, San Diego Wild Animal Park [San Diego Zoo Safari Park], N 33.09153°, W 116.98241°, 20–24 July 2009, coll. USGS, pitfall trap (DMNS ZA.33089); USA: California, San Diego County, San Diego National Wildlife Refuge, N 32.72446°, W 116.94318°, 107 m elev., 3–7 August 2009, coll. USGS, pitfall trap (2 males: DMNS ZA.33091).

Females (5). MÉXICO: Baja California Norte, 2 August 2002, coll. Rcho [sic] & Enriques (IBUNAM no number); USA: California, Riverside County, Santa Rosa Mountains, Highway 74, 1 mile W Pinyon Pines [fire station], N 33.58947°, W 116.47021°, 4000 m elev., 19 July 2005, coll. Wendell Icenogle, one female (collected near a male) on highway in car headlights at 01:30 hr (DMNS ZA.36272); USA: California, San Diego County, San Diego Wild Animal Park [San Diego Zoo Safari Park], N 33.09761°, W 116.98011°, 235 m elev., 12 September–16 January 2011, coll. USGS, pitfall trap (DMNS ZA.33051); USA: California, San Diego County, San Diego Wild Animal Park [San Diego Zoo Safari Park], N 33.09761°, W 116.98011°, 235 m elev., 17–21 August 2009, coll. USGS, pitfall trap (DMNS ZA. 33090); USA: California, San Diego County, Alpine area, N 32.8305°, W 116.76641°, 562 m elev., 15 September 2003, coll. unknown (DMNS ZA.36271).

Diagnosis. Eremocosta bajaensis male chelicera is similar to that of E. calexicensis. It is distinguished by the much smaller and more ridge-like (rather than tooth-like) MM of the movable finger of E. bajaensis (compare Fig. 2A and E), a short but distinct fondal notch; color pattern of propeltidum (compare Fig. 5A and B), with E. bajaensis having a darker anterior edge; and color of appendages. Female genital operculum wings thin and curved (Fig. 4A) and very different from that of E. calexicensis (Fig. 4B).

Measurements. Male holotype. TL 21.0; CL 5.5; CH 2.3; FNL 0.3; FNH 0.6; FFH 0.9; PL 19.2; PT 1.8; PMT 7.0; LI 16.0; LIV 25.0; PPL 4.2; A/CP 6.2; FNL/FNH 0.5; FFH/FNH 1.5.

Males (n = 11). TL 27.0–34.0; CL 7.5–9.1; CH 3.4–4.5. FNL 0.3–1.0; FNH 0.4–1.0; FFH 0.8–1.0; PL 21.0– 34.0; PT 1.9–4.0; PMT 4.0–7.9; LI 14.5–23.0; LIV 26.0–37.0; PPL 3.4–5.0; A/CP 5.1–7.3; FNL/FNH 0.5–1.0; FFH/FNH 0.8–2.1; FFH/ CH 0.2–0.3.

Females (n = 5). TL 30.0–40.0; CL 8.9–12.1; CH 5.0–5.0; PL 21.0–30.0; PT 1.4–2.1; PMT 6.4–6.9; LI 18.0– 21.5; LIV 30.0–35.0; PPL 4.9–6.4; A/CP 4.4–5.5.

Description. Male holotype. Coloration. Overall dusky yellow, appendages the same; propeltidium lightly reticulate brownish-violet with dark anterior edge (Fig. 5A). Pale oval behind eye tubercle (Fig. 5A). No distinct abdominal coloration. Malleoli white.

Chelicera. Male. VDC deep, occupying approximately half the length of fixed finger (Fig. 1A), narrower than E. calexicensis (Fig. 1B). Thin, straight fixed finger with no median dentition; movable finger: MP-MSM-MM (a tiny medial tooth or ridge); MPL distinct (Figs. 2A & B). Fondal notch short; three RFA; fondal teeth graded II, I, III, IV retrolaterally and I, III, II, IV prolaterally (Fig. 3A).

Setation. Male. Typical male setation. Palp with long, thin setae scattered throughout. A pair of long thin setae just proximal to the tibia-femur joint. A few scattered bacilli on the coxa of LII, LIII, and LIV.

Coloration. Female. As in males but slightly lighter.

Chelicera. Female. Fixed finger: FP-2 FSM (posterior being larger)-FM-smaller FSD-FD; Movable finger: MP-2 MSM-MM; MPL distinct (Fig. 2C & D). Two RFA proximal to FP; fondal teeth graded II, I, III, tiny IV retrolaterally and I, III, II, IV prolaterally.

Setation. Female. Typical.

Genital Operculum. All of the females examined match Muma’s illustration (1987, p. 25, fig. 12) with long, curved anterior arms widening at the posterior wing (Fig. 4A). None had the pits on the anterior arms as illustrated in Muma’s fig. 11.

Distribution. Eremocosta bajaensis appears to occupy an area extending from coastal southern California west of the Peninsular Ridge into Baja de Norte, México. This is the species identified as E. spinipalpis by Cushing et al. (2015). A male and female were also collected as far inland as the Santa Rosa Mountains in Riverside County, California. Collections by USGS, San Diego found E. bajaensis from April to September numbering 6 males and 4 females. Muma’s (1951) list of E. calexicensis from coastal California, San Diego Co. may have been this species.