Hogna ingens (Blackwall, 1857)

Crespo, Luis C., Silva, Isamberto, Enguidanos, Alba, Cardoso, Pedro & Arnedo, Miquel, 2022, Island hoppers: Integrative taxonomic revision of Hogna wolf spiders (Araneae, Lycosidae) endemic to the Madeira islands with description of a new species, ZooKeys 1086, pp. 84-135 : 84

Hogna ingens (Blackwall, 1857)

Figures 12 , 13 , 14

Lycosa ingens Blackwall, 1857: 284 (Df).

Lycosa ingens Blackwalli, 1867: 203 (Dm).

Trochosa ingens Kulczynski, 1899: 423, pl. 9, fig. 121 (mf).

Geolycosa ingens Roewer, 1955: 241.

Geolycosa ingens Roewer, 1960: 689, fig. 387e (f).

Hogna ingens Wunderlich, 1992: 459, fig. 720b, fig. 724a.

Types.

Holotype: no type materials from the Blackwall collection were found neither at the OUMNH nor the NHM.

Material examined.

Deserta Grande • Vale da Castanheira (N), 1 ♀ ( SMF21994 ), 26.III.1967, 1 ♀ (CRBALC0591) and 4 juveniles (CRBALC0593, CRBALC0594, CRBALC0595, CRBALC0592), 32.56685°N, 16.53694°W, 25.III.2017, hand collecting, leg. L. Crespo; (unknown location), 3 ♀♀ (MNHNP AR16186) .

Diagnosis.

Hogna ingens can be diagnosed from all other Madeiran Hogna by the aspect of its legs, blackish with white patches (Figs 13 , 26C ), and additionally by its genitalia. In males, according to literature, by the inclined palea shield ( Wunderlich 1992: 596, fig. 720f). In females, by short epigynal anterior pockets, with lateral borders divergent and anteriorly swollen median septum (Fig. 12A ).

Redescription.

Male: We could not examine any male specimens.

Female (CRBALC0591): (Fig. 12 ). Total length 25.1; carapace: 14.8 long, 11.0 wide.

Colour: carapace greyish brown, densely covered with short black setae, with a cream longitudinal band present from fovea to posterior margin of carapace; with two faint light grey marginal bands suffused with black patches, covered with white setae; four striae well visible on each flank. Chelicerae black except apically, reddish brown, covered in black setae. Gnathocoxae and labium overall orange-brown, densely covered with black setae; sternum greyish brown, densely covered with black setae. Legs greyish, with a variable number (6-8) of lightly coloured patches covered by white setae. Pedipalps greyish, densely covered in black setae. Abdomen densely covered in black setae, with only four very small white patches dorsally and a small anterolateral band of white setae; venter densely covered in black setae, with only two faint median bands of small white patches.

Eyes: MOQ: MW = 0.7 PW, MW = 1.2 LMP, MW = 1.1 AW; Cl = 0.5 DAME. Anterior eye row slightly procurved.

Legs: Measurements: Leg I: 37.7, TiI: 8.9; Leg IV: 35.9, TiIV: 8.4; TiIL/D: 2.3. Spination of Leg I: FeI: d1.1.0, p0.0.2; TiI: p0.0.0, v2s.2s.2s; MtI: p0.0.1, r0.0.1, v2s.2s.1s. MtI an TiI with dense scopulae.

Epigyne: anterior pockets far apart, short, with lateral borders anteriorly convergent, then becoming divergent (Fig. 12A ); anterior pocket cavities shallow; median septum anteriorly swollen, with wide posterior transverse part (Fig. 12A ); spermathecae moderately swollen (Fig. 12B ); copulatory ducts basally with a laterally projected bulbus (Fig. 12B ); fertilisation ducts emerging at the base of copulatory duct (Fig. 12B ).

Distribution.

This species is known only from Vale da Castanheira, a 1 km2 valley in the north end of Deserta Grande (Fig. 14 ).

Ecology.

Vale da Castanheira is a semi-arid grassland area.

Conservation status.

Hogna ingens was declared Critically Endangered in previous works ( Cardoso 2014; Crespo et al. 2014b). Its restricted habitat has been subject to biological invasions since humans set foot in Deserta Grande, with the introduction of herbivore vertebrates and, more recently, of the herb Phalaris aquatica L., which grows abundantly throughout the valley, limiting the access of H. ingens to shelter below rocks and fissures and displacing native flora. A recovery program of the valley’s vegetation is being conducted, and recent data indicates the spider population is increasing. An ex-situ breeding program is currently being conducted by the Bristol Zoo to safekeep populational levels.

Figures

Figure 12. Hogna ingens female (CRBALC 0591): A epigyne, ventral B vulva, dorsal. Abbreviations, female genitalia: H - epigynal hoods, MS - median septum, S - spermatheca. Scale bars: 0.5 mm.

Figure 13. Photograph of H. ingens. Female specimen in the field. Photograph credit Pedro Cardoso.

Figure 14. Distribution of H. ingens. Black circles: present records; white triangle: unconfirmed record from literature.

Figure 26. Plate with photographs of the lateral view of the leg I for easily diagnosable species.