Blakistonia Hogg, 1902

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 : 13-14

publication ID	https://doi.org/ 10.11646/zootaxa.4518.1.1
publication LSID	lsid:zoobank.org:pub:708981EF-21DC-4DC2-B1CD-8CFF4373DA8C
DOI	https://doi.org/10.5281/zenodo.5967793
persistent identifier	https://treatment.plazi.org/id/03C10411-555B-FFCB-E1E8-FD3CFDEDFB82
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scientific name	Blakistonia Hogg, 1902
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Genus Blakistonia Hogg, 1902 View in CoL View at ENA

Blakistonia Hogg, 1902: 131 View in CoL . Type species Blakistonia aurea Hogg, 1902 View in CoL , by original designation. Rix et al, 2017c: 582. Cantuarides Strand, 1907: 8 . Type species Cantuarides exsiccatus Strand, 1907 , by original designation (synonymised by Main, 1985: 39).

Diagnosis. Most species of Blakistonia can be distinguished from those of other Arbanitinae by the following combination of characters (sensu Rix et al. 2017c): a relatively narrow carapace in dorsal view (e.g., Figs 5A View FIGURE 5 , 6A View FIGURE 6 ) (relative to species of Euoplos Rainbow, 1914 ); a square or subquadrate eye group (e.g., Figs 5D View FIGURE 5 , 7D View FIGURE 7 ); the presence of scopulae on tarsi I and II of females (e.g., Fig. 18G, H View FIGURE 18 ); and the absence of a distal retrolateral tibial apophysis on the male pedipalp (e.g., Fig. 5J, L View FIGURE 5 ). Species of Blakistonia can be further distinguished from those of most Euoplini, Arbanitini and Aganippini by the square or subquadrate eye group. Some species of Eucyrtops (tribe Aganippini) have a similar subquadrate eye group to species of Blakistonia (e.g., Eucyrtops eremaeus Main, 1957 ), and some Blakistonia can have a marginally trapezoidal eye group (e.g., B. nullarborensis sp. n. [ Fig. 20D View FIGURE 20 ] and B. wingellina sp. n. [ Fig. 28D View FIGURE 28 ]). However, similar species of Aganippini can be distinguished from Blakistonia by a more strongly attenuate base to the RTA ( Rix et al. 2017c). See Rix et al. (2017c) for diagnostic molecular characters.

Description. Small to large idiopid spiders, usually dark brown to golden or orange-brown in colour ( Fig. 1 View FIGURE 1 A–I). Carapace oval-shaped (e.g., Figs 6A View FIGURE 6 , 9A View FIGURE 9 , 10A View FIGURE 10 ), commonly with line of setae between fovea and eye group ( Fig. 8D View FIGURE 8 ), and males with fringe of setae around lateral carapace ( Fig. 14A View FIGURE 14 ); fovea procurved in females and commonly straight in males ( Fig. 5A View FIGURE 5 ) or slightly procurved ( Fig. 6A View FIGURE 6 ). Eye group square ( Fig. 5A View FIGURE 5 ) or subquadrate ( Figs 7D View FIGURE 7 , 22D View FIGURE 22 ), rarely trapezoidal ( Figs 20D View FIGURE 20 , 28D View FIGURE 28 ); anterior eye row always strongly procurved ( Figs 5D View FIGURE 5 , 6D View FIGURE 6 , 7D View FIGURE 7 ). Chelicerae with rastellum of several strong conical spines in both males and females and with a row of teeth on each edge of furrow, the teeth decreasing in size from distal to proximal end. Maxillae rectanguloid, wider behind than in front, with setae becoming longer towards interior margins; maxillary cuspules present in some males ( Fig. 17F View FIGURE 17 ) and all females ( Fig. 6F View FIGURE 6 ), becoming denser towards interior margins; labium wider than long, with slightly recurved or straight posterior edge, with two longer clumps of curved setae on anterior lateral edges; labial cuspules present in some males ( Fig. 14F View FIGURE 14 ) and some females ( Fig. 15F View FIGURE 15 ). Sternum without distinct sigilla or with three distinct pairs in which anterior pair are smallest, the median pair bigger and the posterior pair largest, as in most mygalomorphs. Abdomen oval, typically with chevron pattern dorsally ( Figs 9A View FIGURE 9 , 10A View FIGURE 10 ) and 1–5 pairs of unsclerotised sigilla ( Figs 15A View FIGURE 15 , 28A View FIGURE 28 ) in females and also males of B. olea sp. n., but not distinct in B. nullaborensis . Legs with scopulae ventrally on tarsi I, II ( Fig. 7G, H View FIGURE 7 ) and metatarsi I, II of all females and some males ( Fig. 11A View FIGURE 11 ), and palpal tarsus of females. Male tibia I with either prolateral clasping spurs on tibia I, each with raised cuticular bases and bearing multiple terminal peg-like macrosetae ( Fig. 8 View FIGURE 8 G–I), two prolateral macrosetae ( Fig. 11 View FIGURE 11 G–I), or a single prolateral macroseta ( Fig. 9 View FIGURE 9 G–I). Leg tarsi with three claws, one row of teeth on paired claws; female pedipalp claw without teeth. Male pedipalp with short, pointed RTA with broad base; RTA covered in spinules ( Fig. 14 View FIGURE 14 J–L); cymbium with field of spinules disto-dorsally in most species, sometimes spine-like; embolus simple, slightly twisted, most species with broad base ( Fig. 5 View FIGURE 5 J–L). Spermathecae paired, simple, unbranched, stout and outward facing, oval-shaped in most species, covered in opaque mottled brown glandular nodules ( Fig. 18I View FIGURE 18 ). Four spinnerets, posterior lateral pair three-segmented, apical article short with domed or conical tip, posterior median pair small, digitiform.

Distribution. Blakistonia has a distribution that is centred on southern South Australia ( Rix et al. 2017c), especially Adelaide and the Mount Lofty Ranges, and extending north into the central arid zone and into the southern Northern Territory around Uluru-Kata Tjuta National Park. They are also sparsely distributed in Queensland, western inland New South Wales, western Victoria, south-western Western Australia and eastern inland Western Australia, near the Western Australian/South Australian/ Northern Territory border. Blakistonia are absent from mesic south-eastern Australia (east of the Grampians Range), the northern half of the Northern Territory and most of arid New South Wales and western inland/northern Western Australia (see Rix et al. 2017c, fig. 68 and Figures 29–34 View FIGURE 29 View FIGURE 30 View FIGURE 31 View FIGURE 32 View FIGURE 33 View FIGURE 34 for summary distribution maps.)

Composition. Blakistonia includes one previously described species, B. aurea Hogg, 1902 , and 19 new species: B. bassi sp. n., B. bella sp. n., B. birksi sp. n., B. carnarvon sp. n., sp. n., B. emmottorum sp. n., B. gemmelli sp. n., B. hortoni sp. n., B. mainae sp. n., B. maryae sp. n., B. newtoni sp. n., B. nullarborensis sp. n., B. olea sp. n., B. parva sp. n., B. pidax sp. n., B. plata sp. n., B. raveni sp. n., B. tariae sp. n., B. tunstilli sp. nov. and B. wingellina sp. n.

Biology and remarks. Blakistonia is a diverse group, both in distribution and number of species. Spiders are found in a variety of habitats, from mossy banks in the mesic, high rainfall zone of the Mount Lofty Ranges, to arid desert areas such as those in northern and inland South Australia and Western Australia. The burrows of the most common species, B. aurea , are characteristically D-shaped, slightly indented and plug-like ( Fig. 2B, 2L View FIGURE 2 ); however, other species build a variety of different burrows, including round, indented, plug-like lids ( Fig. 2 View FIGURE 2 F–G, K), wafer-like lids ( Fig. 2D, E View FIGURE 2 ), and also burrows that are twig-lined ( Fig. 2 View FIGURE 2 H–J). Wandering Blakistonia males are usually collected after rainfall events, most frequently in March to May, but have also been collected later in the year from June to September.