Ischnothyreus tadetu, Tong, Yanfeng & Li, Shuqiang, 2013

Tong, Yanfeng & Li, Shuqiang, 2013, Six new species of oonopid spiders from Champasak, Laos (Araneae, Oonopidae), Zootaxa 3709 (1), pp. 71-88 : 73-76

Ischnothyreus tadetu sp. nov.

( Figures 2 , 3 )

Type material: Holotype: Male ( IZCAS AR 19390), Laos, Champasak Province, Tad Etu, Unnamed Waterfall near Holiday Village, 15º11.639'N, 106º06.222'E, elevation 909 meters, November 19, 2012, leg. S. Li.

Etymology: The specific name is a noun in apposition taken from the type locality.

Diagnosis: The new species is similar to I. florifer Kranz-Baltensperger, 2011 , but can be distinguished by the reduced dorsal scutum, the slightly sclerotized process at base of fangs and by the tip of the male palpal bulb.

Description: Male (holotype). Body length 1.69; carapace 0.92 length, 0.64 width; abdomen 0.89 length, 0.46 width. Habitus as in Figs 2 A–C. Carapace: orange-brown, with brown egg-shaped patches behind eyes, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, surface and sides strongly reticulate ( Figs 2 D, E). Eyes: six, well developed, ALE largest, PME smallest; posterior eye row straight from above, procurved from front. Mouthparts ( Fig. 2 F): chelicerae slightly divergent, with slightly sclerotized process at base of fangs (ssp in Fig. 3 D); fang groove with many small denticles ( Figs 2 G, 3D). Anterior margin of labium indented at middle. Anteromedian tip of endites with one strong, tooth-like projection ( Fig. 2 C). Abdomen: scutum extending far dorsal of pedicel. Dorsal scutum covering about 2/3 of abdomen, about 3/4 of abdomen width, fused to epigastric scutum. Epigastric and postepigastric scutum well sclerotized, pale orange, fused. Leg formula: femur I with 2 prolateral and 1 small retrolateral spine, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Leg II spination is similar to leg I except femur with only 1 prolateral spine. Legs III and IV spineless. Genitalia: Sperm pore situated at level of anterior spiracles. Palp strongly sclerotized, trochanter with ventral projection; femur normal size; patella about as long as femur, not enlarged; cymbium not fused with bulb; bulb with one small ventral protuberance (vpr), at the distal end with a membranous outgrowth (ogr) ( Figs 2 H–J, 3A–C). Female: Unknown.

Distribution: Known only from the type locality.

Figures

FIGURE 2. Ischnothyreus tadetu sp. nov., male. A – C. Habitus, dorsal, lateral and ventral views; D – F. Prosoma, dorsal, lateral and anterior views; G. Left chelicera, frontal view; H – J. Left palp, prolateral, dorsal and retrolateral views. Scales: A – C = 0.4 mm; D – F = 0.2 mm; G – J = 0.1 mm.

FIGURE 3. Ischnothyreus tadetu sp. nov., male. A – C. Left palp, prolateral, retrolateral and dorsal views; D. Left chelicera, frontal view. Abbreviations: ogr, outgrowth; ssp, slightly sclerotized process; vpr, ventral protuberance. Scales: 0.05 mm.