Diamphidaxona cavecreekensis, Smith, Ian M. & Cook, David R., 2006

Smith, Ian M. & Cook, David R., 2006, North American species of Diamphidaxona (Acari: Hydrachnida: Hygrobatidae), Zootaxa 1279, pp. 1-44 : 12-13

Diamphidaxona (s. s.) cavecreekensis sp. nov.

( Figs. 42–46 )

Description. Female with character states of Diamphidaxona (s. s.) (male unknown). Dorsal edge of camerostome rounded anteriorly and not projecting to anterior end of idiosoma ( Fig. 43 ). Pedipalps with tibia bearing one ventral seta and tarsus with ventral spine­like seta bearing two straight or slightly curved denticles ventrally ( Fig. 44 ). Dorsal shield with anterior plate of same width as posterior plate and rounded anteriorly ( Fig. 42 ). Ventral shield with suture lines between third and fourth coxal plates with medial loops shallow and lateral loops U­shaped and open anteriorly ( Fig. 43 ). Projections covering insertions of fourth pair of legs with anterior extensions long and directed anteriorly parallel to edges of ventral shield ( Fig. 43 ). Measurements: Female (n=5): Length/width anterior dorsal plate 158–173/223–257 (162/257), length/width posterior dorsal plate 295–322/243–262 (317/262), length/width ventral shield 416–441/272–307 (431/302), width genital field 104–109 (104). Lengths pedipalp segments: Tr 15–20 (16), Fe 55–58 (58), Ge 38–45 (45), Ti 54–63 (59), Ta 25–28 (25). Lengths leg segments: ITr 35–38 (38), IBFe 50–56 (53), ITFe 53–55 (55), IGe 58–66 (66), ITi 63–70 (70), ITa 73–76 (75); IITr 38–40 (40), IIBFe 50–58 (55), IITFe 50–55 (53), IIGe 55–63 (63), IITi 58–65 (65), IITa 63–75 (74); IIITr 33–38 (35), IIIBFe 48–55 (55), IIITFe 48–53 (53), IIIGe 58–65 (65), IIITi 63–68 (68), IIITa 73–78 (75); IVTr 78–85 (85), IVBFe 73–80 (80), IVTFe 80–90 (88), IVGe 88–103 (103), IVTi 95–105 (100), IVTa 93–98 (98).

Types. Holotype: Female from Cave Creek at Stewart Campground, Chiricahua Mountains west of Portal, Cochise Co. , Arizona on 16 July 1987 by IMS (slide, CNC). Paratypes: Arizona: Cochise Co. : Chiricahua Mountains west of Portal: same locality as holotype (at or just above Stewart Campground), 15 May 1991, IMS — 2 females (slides, CNC); 9–11 October 1993, IMS — 6 females (slides, CNC); 3 March 1998, IMS — 1 female (slide, CNC); 19–21 May 2000, IMS — 6 females (slides, CNC); 30 April 2001, IMS — 1 female (slide, CNC); Cave Creek at John Hand Picnic Area off Forest Road 42A, 1 March 1999, IMS — 1 female (slide, CNC); Cave Creek below dam at Herb Martyr Campground off Forest Road 42A, 28 April 2001, IMS — 1 female (slide, CNC); North Fork of Cave Creek beside Forest Road 42, 1.3–1.9 km above Forest Road 42A, 23 May 2000, IMS — 1 female (slide, CNC); 29 April 2001, IMS — 3 females (slides, CNC); 8–14 September 2001, IMS — 2 females (slides, CNC); 6–7 May 2002, IMS — 2 females (slides, CNC). Chiricahua Mountains east of Sunizona, Turkey Creek (West Turkey Creek) at Sycamore Campground, 15 October 1993, IMS — 1 female (slide, CNC). New Mexico: Catron Co.: Little Creek beside Little Creek Trail off Rt. 15, 63 km (39 miles) north of Rt. 180 in Silver City, 10 July 1987, IMS — 2 females (slides, CNC).

Etymology. Named for Cave Creek in the Chiricahua Mountains where most of the known specimens of this species have been collected.

Distribution. Streams in the Chiricahua Mountains of southeastern Arizona and Gila Mountains of southwestern New Mexico.

Remarks. Adults of Diamphidaxona cavecreekensis resemble those of the preceding three species and the following two species in that the projections covering the insertions of the fourth pair of legs are long and extend anteriorly parallel to the edges of the ventral shield, but differ from all other species except D. chiricahua in that the suture lines between the third and fourth coxal plates have the medial loops relatively shallow. They differ from adults of D. chiricahua in being much smaller in size and having the posterior dorsal plate slightly widened near its midlength and the leg segments relatively short and stocky.

Figures

FIGURES 42 – 46. Diamphidaxona (s. s.) cavecreekensis sp. nov., adult female. 42, dorsal shield; 43, ventral shield and genital field; 44, pedipalp; 45, leg I; 46, distal segments of leg IV.