Diamphidaxona (Diamphidaxonella) neomexicana, 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 : 18-19

Diamphidaxona (Diamphidaxonella) neomexicana sp. nov.

( Figs. 62–68 )

Description. Character states of Diamphidaxonella. Dorsal edge of camerostome acutely rounded anteriorly ( Figs. 64, 67 ). Pedipalps with tibia bearing two ventral setae ( Fig. 66 ). Dorsal shield with anterior plate of same width as posterior plate and rounded anteriorly ( Fig. 62 ). Ventral shield with suture lines between third and fourth coxal plates with medial loops deeply arched and lateral loops U­shaped and open anteriorly ( Figs. 64, 67 ). Projections covering insertions of fourth pair of legs with anterior extensions moderately long, sinuous and directed anterolaterally ( Figs. 64, 67 ). Genital field of males separated from ventral shield by distinct band of membranous integument ( Fig. 64 ). Measurements: Male (n=3): Length/width anterior dorsal plate 124–149/233–248, length/width posterior dorsal plate 277–282/243–248, length/width ventral shield 391–421/277–292, length/ width genital field 50–59/99–104. Lengths pedipalp segments: Tr 13, Fe 45–48, Ge 20–21, Ti 28–30, Ta 18–20. Lengths leg segments: ITr 35–38, IBFe 40–45, ITFe 40–43, IGe 50, ITi 53–55, ITa 60–65; IITr 40, IIBFe 40–43, IITFe 43–45, IIGe 48–50, IITi 53–55, IITa 63–73; IIITr 33, IIIBFe 48–50, IIITFe 43–45, IIIGe 50–53, IIITi 60–63, IIITa 75; IVTr 75–80, IVBFe 58–65, IVTFe 65–68, IVGe 75–78, IVTi 75–78, IVTa 78. Female (n=5): Length/width anterior dorsal plate 153–174/252–270 (174/270), length/width posterior dorsal plate 306–327/267–276 (306/270), length/width ventral shield 446–480/299–330 (480/330), width genital field 106–114 (109). Lengths pedipalp segments: Tr 13–15 (14), Fe 48–53 (52), Ge 22–25 (22), Ti 29–31 (31), Ta 22–24 (22). Lengths leg segments: ITr 36–45 (39), IBFe 43–49 (49), ITFe 42–48 (47), IGe 49–55 (52), ITi 52–58 (53), ITa 63–73 (73); IITr 39–43 (39), IIBFe 45–51 (51), IITFe 42–47 (47), IIGe 51–55 (53), IITi 53–60 (59), IITa 68–73 (69); IIITr 38–45 (39), IIIBFe 48–52 (52), IIITFe 43–48 (44), IIIGe 52–58 (56), IIITi 64–65 (65), IIITa 75–81 (81); IVTr 83–91 (91), IVBFe 65–70 (68), IVTFe 68–73 (72), IVGe 78–85 (85), IVTi 80–86 (86), IVTa 72–80 (78).

Types. Holotype: Female from Little Creek beside Little Creek Trail off Rt. 15, 63 km (39 mi.) north of Rt. 180 in Silver City, Catron Co., New Mexico on 17 May 1991 by IMS (slide, CNC). Paratypes: USA: New Mexico: Catron Co.: Same data as holotype — 1 female (slide, CNC). Same locality as holotype, 18 May 2000, IMS — 1 male, 4 females (slides, CNC); 13 May 2002, IMS — 3 females (slides, CNC). Grant Co.: Sapillo Creek beside Sapillo Creek Trail 2.4 km (1.5 mi.) west of trail head at Rt. 15 just south of Rt. 35, 11 May 2002, IMS — 2 males, 1 female (slides, CNC).

Etymology. Named for the state of New Mexico where all known specimens of this species were collected.

Distribution. Streams in the Gila Mountains of western New Mexico.

Remarks. Adults of Diamphidaxona neomexicana differ from those of all other known North American species of the subgenus Diamphidaxonella in that the segments of the pedipalp are very short and stocky and the tibia bears two ventral setae and in that the anterior dorsal plate is rounded anteriorly.

Figures

FIGURES 62 – 68. Diamphidaxona (Diamphidaxonella) neomexicana sp. nov., adults. 62, dorsal shield, female; 63, distal segments of leg IV, female; 64, ventral shield and genital field, male; 65, leg I, female; 66, pedipalp, female; 67, ventral shield and genital field, female; 68, gnathosoma, lateral view, female.