Hogna arborea, Lo & Wei & Cheng, 2023

Lo, Ying-Yuan, Wei, Chi & Cheng, Ren-Chung, 2023, Tree-dwelling wolves: a new arboreal Hogna species (Araneae: Lycosidae) from Taiwan, Zootaxa 5353 (1), pp. 47-59 : 51-54

Hogna arborea sp. nov.

Figs 3–5

Type material. Holotype: female (TESRI-Ar3045), 4 Dec. 2018, Ying-Yuan Lo leg., Dongao, Yilan County (24.53°N, 121.83°E) . Paratypes: one male (TESRI-Ar5507), 10 Feb. 2020, Chi-Chun Liao leg. (reared in lab and matured on 24 Aug. 2020), Saguer Trail, Hualian County (24.01°N, 121.58°E) ; one female (TESRI-Ar3549), 23 Dec. 2019, Chi-Chun Liao leg., same locality as the holotype ; one female (TESRI-Ar5523), 26 Mar. 2016, Chen-Fu Hsu leg., Lijia Forest Trail, Taitung County (22.80°N, 121.05°E) ; one female (TESRI-Ar5753), 3 Jan. 2021, Chang-Lin Chung leg., Kenting National Park , Pingtung County (21.95°N, 120.81°E) .

Other material examined: two males (TESRI-Ar3562/3563), 10 Oct. 2001, Ren-Jie Chen leg. Kenting National Park , Pingtung County (21.95°N, 120.81°E) .

Diagnosis. Hogna arborea sp. nov., is similar to H. trunca Yin, Bao & Zhang, 1996 in the female epigyne, the shape of inversed T-shaped septal pedicel, and in the median apophysis of male palp organ with a triangular prominence toward the ventral side. However, H. arborea sp. nov., can be distinguished from the latter by its vulva with a pair of large, leaf-like massive folds, septum pedicel of epigyne narrower and conspicuously constricted anteriorly ( Figs 3A–B , 4 A–B ), apex of the cymbium of male pedipalp not hook-shaped and without a bent ventrally ( Figs 3E , 4E ; ventrally bent apex in H. trunca — Shida 2022: Fig. 3D ), and a palea proportionally larger.Additionally, specimens of H. arborea sp. nov. (females 20.6–21.2 mm; male 19.5 mm) are larger than those of H. trunca (females 14.7–21.4 mm; males 13.0– 15.6 mm; see Yin et al. 1996 and Shida 2022).

Description. Female (TESRI-Ar3045, holotype). Total length 20.6, carapace length 10.0, width 8.3; Opistosoma length 10.6, width 8.0. Prosoma in lateral view with gradually descending thoracic region, ocular area not elevated ( Fig. 5C ). Carapace yellowish with a distinct brown central band from PME to posterior margin, and a pair of black, irregular inner edge stripes on lateral region. Fovea longitudinal, cervical and radical grooves indistinct. Clypeus, AER and PME region black, AER straight and PER strongly recurved. AME slightly larger than ALE, and width of AER approximately equal to those of SER ( Fig. 5E ). Eye diameters and interdistances: AME 0.50, ALE 0.40, PME 1.0, PLE 0.9; MOA-L 1.70, MOA-AW 1.30, MOA-PW 2.60; AME-AME 0.20, AME-ALE 0.20, PME-PME 0.90, PME-PLE 1.00; clypeus height 0.50. Chelicerae massive, black with several reddish setae at the frontside. Chelicera furrow with one promarginal tooth and three retromarginal teeth. Endites and labium black. Sternum black, heart-like, densely covered by setae. Legs strong, yellowish with black annular patches and armed with several macrosetae. Venter of coxa black while alive. Metatarsus and tarsus I + II with well-developed scopulae ( Fig. 5G ). Measurements of pedipalps and legs: pedipalp 11.5 (4.0, 1.9, 2.4, 3.2), leg I 32.4 (8.7, 3.5, 7.0, 9.4, 3.8), leg II 25.0 (7.1, 3.3, 5.3, 6.1, 3.2), leg III 26.1 (7.5, 3.5, 5.8, 6.0, 3.3), leg IV 28.2 (8.1, 4.0, 6.4, 6.2, 3.5). Opistosoma oval, dark brown, with a dark cardiac mark and four black transverse lines behind the cardiac mark ( Fig. 5A ). Sides black with scattered brown spots. Venter almost black.

Epigyne ( Figs 3A , 4A ) with a pair of anterior hoods. Median septum inverted T-shaped, middle part widest and anterior constricted. Length of septum longer than width of septal base. Internal genitalia with a pair of massive, leaf-like and wiggly folds ( Figs 3B , 4B ). Spermathecae columnar with irregular projections on the tip.

Male (TESRI-Ar5507, paratype). Body shape and color pattern similar to females ( Fig. 5B ), but the prosoma in lateral view is obviously inclined behind fovea ( Fig. 5D ). Total length 19.5, carapace length 10.0, width 8.0; opistosoma length 9.5, width 7.2. AER approximately equal to SER ( Fig. 5F ). Eye diameters and interdistances: AME 0.50, ALE 0.40, PME 0.9, PLE 0.9; MOA-L 1.60, MOA-AW 1.30, MOA-PW 2.30; AME-AME 0.30, AME-ALE 0.20, PME-PME 0.90, PME-PLE 0.80; clypeus height 0.30. Measurements of pedipalps and legs: pedipalp 11.9 (4.1, 1.9, 2.4, 3.5), leg I 33.1 (9.3, 4.1, 7.4, 8.3, 4.0), leg II 31.7 (9.2, 4.0, 8.6, 7.7, 4.0), leg III 29.2 (8.7, 3.6, 5.9, 7.4, 3.6), leg IV 36.3 (10.3, 3.8, 7.7, 10.5, 4.0).

Palp organ ( Figs 3C–E , 4C–E ). Cymbium 2.2 times longer than wide, with two claws and a bunch of apical macrosetae. Palea with two sickle-shaped terminal apophysis, one of which is parallel and behind embolus. Subtegulum much smaller than tegulum. Median apophysis large and transverse, with a retrolateral pointed tip and a triangular prominence toward the ventral side. Embolus curved, tapering on the tip behind the median apophysis.

Variation. As male specimens were damaged except one paratype, measures of morphological variation were based solely on female specimens. Values indicate mean ± standard deviation. Total length 20.9 ± 0.3, carapace length 10.2 ± 0.2, width 8.7 ± 0.5; opisthosoma length 10.6 ± 0.2, width 8.1 ± 0.6. Diameters of AME 0.53 ± 0.06, ALE 0.40 ± 0.00, PME 1.00 ± 0.00, PLE 0.9 ± 0.00, MOA-AW 1.37 ± 0.12, MOA-PW 2.63 ± 0.06, MOA-L 1.77 ± 0.12, AME-I 0.23 ± 0.06, PME-I 0.87 ± 0.06, AML-I 0.20 ± 0.00, PML-I 1.03 ± 0.06; Clypeus height 0.53 ± 0.06. Pedipalp 12.3 ± 0.8, leg I 31.1 ± 1.3, leg II 27.5 ± 2.2, leg III 26.7 ± 0.7, leg IV 32.5 ± 3.8.

Distribution. Known only from southern and eastern Taiwan ( Fig. 1 ).

Etymology. The specific epithet “ arborea ” is a Latinized adjective referring to the tree-dwelling natural history of the species.

DNA Barcode and phylogeny. The COI alignment in our analysis consists of 669 base pairs and includes 41 terminals. The ML phylogenetic tree showed that Hogna arborea sp. nov. were placed within a clade with most other Hogna species, including the type species, H. radiata ( Fig. 6 ). On the other hand, the intraspecific genetic distance (K2P) of H. arborea was 0.23%, and the minimum interspecific genetic distance was 6.28% compared to congeners ( Table 2 ). Therefore, the result confirmed that H. arborea sp. nov. from Taiwan is an independent species according to “10X rule” ( Hebert et al. 2004; Yang & Rannala 2017), and the threshold between 1.2% and 3.6% for lycosids (according to Čandek & Kuntner 2015).

Figures

FIGURE 1. Collection localities of Hogna arborea sp. nov. from Taiwan in the present study.

FIGURE 3 A–E. Epigyne and left palp organ of Hogna arborea sp. nov. (A–B, Holotype, TESRI- Ar3045; C–E, Paratype, TESRI-Ar5507). A, ventral view; B, dorsal view; C, prolateral view; D, ventral view; E, retrolateral view. Scale bar = 0.05mm. Abbreviations: BS- base of spermatheca, C- conductor, CD- copulatory duct, Em- embolus, H- hood, HS- head of spermatheca, MA- median apophysis, MF- massive fold, P- palea, S- septum, SB- septum base, St- subtegulum, T- tegulum, TA- terminal apophysis.

FIGURE 4 A–E. Epigyne and left palp organ of Hogna arborea sp. nov. (A–B, Holotype, TESRI- Ar3045; C–E, Paratype, TESRI-Ar5507). A, ventral view; B, dorsal view; C, prolateral view; D, ventral view; E, retrolateral view. Scale bar = 0.05mm. Abbreviations: BS- base of spermatheca, C- conductor, CD- copulatory duct, Em- embolus, H- hood, HS- head of spermatheca, MA- median apophysis, MF- massive fold, P- palea, S- septum, SB- septum base, St- subtegulum, T- tegulum, TA- terminal apophysis.

FIGURE 5 A–G. Habitus of Hogna arborea sp. nov. (A, C, E, G, Holotype, TESRI- Ar3045; B, D, F, Paratype, TESRI- Ar5507). A–B, general appearance, dorsal view; C–D, prosoma, lateral view; E–F, eyes; G, metatarsus I and tarsus I, prolateral view. Scale bar = 5mm (A–D); 0.5mm (E–F), 1mm (G).

FIGURE 6. Maximum likelihood phylogenetic tree of Hogna arborea sp. nov. and related species based on COI gene dataset. Number above branches are ultrafast bootstrap (UFBoot) and SH-like approximate likelihood ratio test (SH-aLRT) values (both values less than 70 were omitted). Scale bar shows substitutions per site. Species marked with an asterisk indicates the type species of the genus.