Blakistonia tariae, Harrison & Rix & Harvey & Austin, 2018

Harrison, Sophie E., Rix, Michael G., Harvey, Mark S. & Austin, Andrew D., 2018, Systematics of the Australian spiny trapdoor spiders of the genus Blakistonia Hogg (Araneae: Idiopidae), Zootaxa 4518 (1), pp. 1-76 : 62-64

Blakistonia tariae , sp. n.

( Fig. 26 A–L)

Type material. AUSTRALIA: Western Australia: Holotype male, Coolinup Nature Reserve , 33°43’53”S, 122°17’50”E, 2 May–29 November 2000, pitfall, P. Van Heurck, Salinity Action Plan Survey (WAM T139466 ). Paratype: 1 male, same data ( WAM T142374 ) .

Other material examined. AUSTRALIA: Western Australia: 1 male, Durokoppin Nature Reserve , 31°24’S, 117°45’E, 11 August–9 September 1990, pitfall, B. Main (WAM T139467 ).

Diagnosis. Males of B. tariae can be distinguished from those of B. bella , B. pidax , B. tunstilli , B. emmottorum , B. gemmelli , and B. aurea by the absence of prolateral clasping spurs on tibia I ( Fig. 26 G–L); from those of B. plata , B birksi , B. newtoni , and B. hortoni by the presence of two, rather than one, prolateral macrosetae on tibia I ( Fig. 26 G–I); from those of B. parva and B. maryae by an eye group that is wider than long ( Fig. 26D ), and from B. olea , B. carnarvon and B. raveni by the combined presence of AME that are similar or smaller in diameter relative to the ALE ( Fig. 26D ), and a carapace that is fairly uniform in colour, with no distinct ring of dark colour around edge of carapace ( Fig. 26A ). Females are unknown.

Description. Holotype male (WAM T139466). Small idiopid spider (total length 6.7). Colour (in ethanol; Fig. 26 A–C): Legs, pedipalp and carapace dark red-brown, darker around caput and anterior margin ( Fig. 26A ); sternum light golden-yellow; labium and maxillae same yellow as sternum, chelicerae similar dark red-brown as anterior end of carapace ( Fig. 26E, F ); abdomen medium brown with no noticeable chevron pattern ( Fig. 26A, C ).

Cephalothorax: Carapace 3.5 long, 2.5 wide, 1.8 high, 1.4 times longer than wide; oval ( Fig. 26A ), caput low, ocular area raised ( Fig. 26C ); cuticle smooth, with pits outward from fovea and both sides of caput; fovea straight; row of three thick setae between fovea and eye group, culminating in several longer, thickened setae directly posterior to eye group; carapace very sparsely setose, with indistinct lines of setae radiating outwards from fovea, concentrated and form fringe on lateral margins; median clump of thickened setae on clypeus ( Fig. 26D ). Length of median clypeus less than 1.0; anterior margin slightly convex. Eye group 0.6 wide, 1.6 long, 0.2 of carapace width; anterior eye row strongly procurved, PLE–PLE/ALE–ALE ratio 1.0; posterior eye row straight; AME similar in size to ALE and separated by about half ALE diameter ALE; PLE just over half of ALE and separated by about ALE diameter; PME pale, about half of PLE, and separated from PLE by less than half its own diameter ( Fig. 26D ). Labium without cuspules ( Fig. 26F ). Sternum 1.6 long, 2.0 wide, evenly setose; sigilla indistinct ( Fig. 26E ). Maxillae without cuspules ( Fig. 26E, F ).

Legs: diffusely setose and spinose on all surfaces; tarsi I, II slightly ventrally swollen; tarsi I, II weakly scopulate ( Fig. 26 G–I). Paired tarsal claws: leg I p5 (5 large) r5 (5 large); leg II p4 (4 large), r6 (5 large, 1 small); leg III p3 (3 large), r2 (2 large); leg IV p5 (2 large, 3 small, r3 2 large, 3 small).

Spination: Tibia I with two prolateral macrosetae ( Fig. 26 G–I). All other legs diffusely setose and spinose, with no clear demarcation between lanceolate setae and smaller spine-like setae.

Leg and pedipalp measurements: Length of legs IV> I> II> III. Leg I: femur 3.4, patella 1.6, tibia 2.4, metatarsus 2.2, tarsus 1.5, total = 11.1. Leg II: femur 3.1, patella 1.4, tibia 2.3, metatarsus 1.9, tarsus 1.3, total = 10.0. Leg III: femur 2.6, patella 1.3, tibia 1.8, metatarsus 2.1, tarsus 1.5, total 1.5. Leg IV: femur 3.2, patella 1.7, tibia 3.5, metatarsus 3.2, tarsus 1.7, total = 13.4. Pedipalp: femur 1.9, patella 1.0, tibia 1.6, tarsus 0.7, total = 5.2.

Pedipalp: Femur with dorsal spines, patella with thickened ventral setae; tibia short and swollen, RTA short and pointed, covered in short, dense spinules for ca. half distance between base of apophysis and distal tibia, becoming more sparse towards distal tibia; long, erect setae on ventral tibia; bulb uniform, globular; embolus simple, slender, tapering, tip slightly twisted, ca. twice length of bulb; cymbium covered in fine setae, without spinules ( Fig. 26 J–L).

Abdomen: Setose, oval, dorsal sigilla not evident; 3.2 long, 2.0 wide ( Fig. 26A ).

Variation (n=2): Carapace 3.4–3.6 long, 2.7 wide, 0–2 labial cuspules.

Etymology. This species is named in honour of Tari Pawlyk, for her environmental work in the Western Australian Goldfields and her love of the Esperance beaches.

Distribution. Blakistonia tariae is known from Coolinup National Park (near Esperance), and Durokoppin Nature Reserve, both in south-western Australia ( Fig. 33 ).

Remarks. The spiders found in Coolinup Nature Reserve (WAM T139466 and T142374) were collected as part of the ‘Salinity Action Plan Survey’ (see Keighery 2004). The spider from Durokoppin Nature Reserve was found in ‘Transect F’.

Figures

FIGURE 26. Blakistonia tariae sp. n., holotype male (WAM T139466): A, habitus, dorsal view; B, habitus, ventral view; C, habitus, lateral view; D, eye group, dorsal view; E, sternum, ventral view; F, maxillae and labium, ventral view; G, left leg I, prolateral view; H, left leg I, macrosetae, prolateral view; I, left leg I, ventral view; J, left pedipalp, prolateral view; K, left pedipalp, retrolateral view; L, left pedipalp, proventral view. Scale bars = 2 mm (A, G), 1 mm (J).

FIGURE 33. Distribution of Blakistonia species: B. mainae sp. n. (white circle), B. wingellina sp. n. (white triangle), B. olea sp. n. (white square), B. nullarborensis sp. n. (black squares), Blakistonia ‘sp. 1’ (black circle), and B. tariae sp. n. (black triangles).