Diamphidaxona (Diamphidaxonella) arizonica, 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 : 22-23

Diamphidaxona (Diamphidaxonella) arizonica sp. nov.

( Figs. 87–94 )

Description. Character states of Diamphidaxonella. Dorsal edge of camerostome sharply pointed anteriorly ( Figs. 89, 92 ). Pedipalps with tibia bearing one ventral seta ( Fig. 91 ). Dorsal shield with anterior plate of same width as posterior plate and weakly pointed anteriorly ( Fig. 87 ). Ventral shield with suture lines between third and fourth coxal plates with medial loops deeply arched and lateral loops U­shaped and open anteriorly ( Figs. 89, 92 ). Projections covering insertions of fourth pair of legs with anterior extensions moderately long, sinuous and directed anterolaterally ( Figs. 89, 92 ). Genital field of males separated from ventral shield by distinct band of membranous integument ( Fig. 89 ). Measurements: Male (n=3): Length/width anterior dorsal plate 150–162/228–252 (150/ 234), length/width posterior dorsal plate 294–306/234–252 (306/234), length/width ventral shield 402–444/264–288 (420/264), length/width genital field 59–64/86–107 (59/ 94). Lengths pedipalp segments: Tr 13–14 (14), Fe 39 (39), Ge 21–22 (22), Ti 30–32 (30), Ta 21–23 (23). Lengths leg segments: ITr 35–38 (35), IBFe 44–46 (44), ITFe 42–44 (42), IGe 48–52 (48), ITi 55–57 (56), ITa 70–72 (70); IITr 40 (40), IIBFe 43–46 (43), IITFe 42 (42), IIGe 49–53 (53), IITi 57–60 (60), IITa 69–73 (73); IIITr 39­40 (40), IIIBFe 44–51 (44), IIITFe 39–44 (44), IIIGe 49–53 (52), IIITi 59–64 (59), IIITa 72–75 (72); IVTr 75–77 (77), IVBFe 62–67 (62), IVTFe 70–72 (70), IVGe 73–78 (77), IVTi 73–77 (73), IVTa 77–79 (79). Female (n=1): Length/width anterior dorsal plate 156/240, length/width posterior dorsal plate 312/252, length/width ventral shield 444/300, width genital field ­. Lengths pedipalp segments: Tr 13, Fe 44, Ge 22, Ti 33, Ta 22. Lengths leg segments: ITr 39, IBFe 52, ITFe 43, IGe 53, ITi 64, ITa 72; IITr 44, IIBFe 51, IITFe 43, IIGe 49, IITi 60, IITa 75; IIITr 38, IIIBFe 49, IIITFe 42, IIIGe 55, IIITi 68, IIITa 78; IVTr 85, IVBFe 70, IVTFe 72, IVGe 82, IVTi 79, IVTa 79.

Types. Holotype: Male from Sycamore Creek off Rt. 87 south of Sunflower (at Round Valley or Circle Bar Ranch), Maricopa Co. , Arizona on 24 June 1992 by SM Clinton (slide, CNC). Paratypes: USA: Arizona: Maricopa Co. : Same data as holotype — 1 male (slide, CNC). Sycamore Creek off Rt. 87 south of Sunflower at Round Valley — 1 male, 17 June 1992, SM Clinton (slide, CNC). Yavapai Co.: West Clear Creek at Clear Creek Campground off Rt. 260 (formerly Forest Road 9) east of Camp Verde — 1 female, 19–22 July 1987, IMS (slide, CNC).

Etymology. Named for the state of Arizona where all of the known specimens of the species were collected.

Distribution. Streams in the desert mountain ranges of southcentral Arizona.

Remarks. Adults of Diamphidaxona arizonica are similar to those of D. californica but differ in that the anterior plate of the dorsal shield is relatively short and only weakly pointed anteriorly.

Figures

FIGURES 87 – 94. Diamphidaxona (Diamphidaxonella) arizonica sp. nov., adults. 87, dorsal shield, female; 88, distal segments of leg IV, male; 89, ventral shield and genital field, male; 90, leg I, male; 91, pedipalp, male; 92, ventral shield and genital field, female; 93, distal segments of leg IV, female; 94, gnathosoma, lateral view, male.