Pholcus pajuensis Lee, Choi and Kim, 2021

Lee, Jun-Gi, Lee, Jun-Ho, Choi, Doo-Young, Park, Sun-Jae & and, A-Young Kim, 2021, Four new species of the genus Pholcus Walckenaer (Araneae, Pholcidae) from Korea, Journal of Species Research 10 (1), pp. 86-98 : 91-93

Pholcus pajuensis Lee, Choi and Kim sp. nov.

( Figs. 1C, D , 2B , 5 , 6 )

Korean name: Ŕ÷Îffîḍ (̎ḋ)

Type material. Holotype, ♂, Korea: Gyeonggi-do, Paju-si, Jeokseong-myeon, near Gloucester Valley Battle Monument (37°56′51″N, 126°55′58″E), 03 Jul. 2016, JG Lee and JH Lee leg. ( NIBR) . Paratype, $, same data as for holotype ( KNU) .

Other materials examined. 1♂ 1$, same data as for holotype ( KNU) ; 16♂♂ 15$$, Gyeonggi-do, Paju-si, Gwangtan-myeon, Bokwangsa Temple valley in Mt. Goryeongsan (37°45′10″N, 126°55′01″E), 01 Jun. 2014, DY Choi leg. ( KISE) .

Etymology. The specific epithet is derived from the type locality, Paju.

Diagnosis. This species can be distinguished from the other Pholcus species by the combination of following characteristics: Male - procursus tip with a round prolateral process with 2 spikes; posterior edge of uncus extended and distally sharpened; pseudo-appendix present, slender and distally hook-shaped; Female - sclerotized anterior arch of internal genitalia slightly curved roundly; postero-lateral portion of internal genitalia with flower-bud like modification.

Description. Male (holotype). Somatic morphology ( Fig. 1C, D ) follows the description of species-group. Total length 5.91. Prosoma 1.76 long, 1.61 wide. Diameter of AME 0.11, ALE 0.16, PME 0.17, PLE 0.16. AME- AME 0.04, AME- ALE 0.03, PME- PME 0.23. Chelicera ( Fig. 2B ) with a thumblike lateral proximal apophysis, a round frontal proximal apophysis and a notched triangular distal apophysis. Sternum 0.82 long, 1.14 wide. Opisthosoma 3.97 long, 1.73 wide. Leg Ⅰ 47.26 (19.2:1.0:18.9:32.3: 3.6), Leg II 31.49 (14.1: 1.0: 12.5: 20.5: 2.7), Leg III 22.16 (10.4: 1.0: 8.6: 13.3: 1.9), Leg IV 29.18 (13.6: 1.0: 10.9: 17.3: 2.1). Leg formula 1243. Palp ( Fig. 5 ). Trochanter apophysis much shorter than femur, slender and triangular, distally blunt, not curved; femur ventrally swollen roundly; tibia with a prolatero-ventral tubercle; procursus dark brown, bent perpendicularly, with 2 ventral knees, dorsally roundly swollen; procursus tip with a retrolateral process with 3 ridges, prolateral round process with 2 spikes and a sharpened ventral process; genital bulb round, pale yellow; uncus dark reddish brown, oval, with many tiny tubercles and posteriorly extended and sharpened; pseudo-appendix dark reddish brown, slender and distally curved like a hook; embolus weakly sclerotized, pale yellow, longer than pseudo-appendix.

Female (Paratype). Somatic morphology follows the description of the species-group. Total length 5.40. Prosoma 1.58 long, 1.46 wide. Diameter of AME 0.10, ALE 0.14, PME 0.17, PLE 0.16. AME- AME 0.04, AME- ALE 0.03, PME- PME 0.22. Sternum 0.80 long, 1.07 wide. Opisthosoma 3.40 long, 1.35 wide. Leg Ⅰ 33.13 (13.9:1.0: 13.5:21.6:3.5), Leg II 22.40 (12.3:1.0:10.8:16.5:2.5), Leg III 16.57 (9.9: 1.0: 8.3: 12.4: 2.2), Leg IV 22.80 (12.2:1.0: 10.1:15.2:2.2). Leg formula 1423. Epigyne ( Fig. 6A ). Anterior cuticle triangular, grayish brown; epigynal plate bright ivory, height about 1/2 of anterior cuticle height, lateral portion slightly extended posteriorly, gradient melanization covering about half of lateral portion of epigynal plate; epigynal knob small and thin, yellowish brown. Internal genitalia ( Fig. 6B ). Anterior arch slightly curved roundly, reddish brown, length as width of epigyne, distinctly visible through epigynal anterior cuticle; postero-lateral portion with flower-bud like modification; pore plate round, small as epigynal knob.

Variation. Male (n = 10) total length 5.06-6.15. Prosoma length 1.54-1.76, width 1.49-1.72. Tibia of Leg Ⅰ 10.46- 12.44.

Female (n = 10) total length 5.21-5.84. Prosoma length 1.48-1.62, width 1.39-1.57. Tibia of Leg Ⅰ 7.43-9.03.

Distribution. Korea (Paju).

Remarks. The female of P. pajuensis is very similar to Pholcus woongil , having a distinct anterior arch of the internal genitalia and gradient melanization on the lateral portion of the epigynal plate. However, this species can be easily distinguished from the latter by following characteristics: anterior arch of internal genitalia round (W-shaped in P. woongil ); presence of postero-lateral flower-bud like modification of internal genitalia (absent in P. woongil ); pore plate small and round (oblong in P. woongil ).

Figures

Fig. 1. Habitus of new Pholcus species, dorsal view (A, C, E, G, male, B, D, F, H, female).A, B, P. chuncheonensis Lee, Choi and Kim sp. nov.; C, D, P. pajuensis Lee, Choi and Kim sp. nov.; E, F, P. pocheonensis Lee, Choi and Kim sp. nov.; G, H, P. unaksanensis Lee, Choi and Kim sp. nov. Scale bars=1 mm.

Fig. 2. Chelicerae of new Pholcus species, frontal view. A, P. chuncheonensis Lee, Choi and Kim sp. nov.; B, P. pajuensis Lee, Choi and Kim sp. nov.; C, P. pocheonensis Lee, Choi and Kim sp. nov.; D, P. unaksanensis Lee, Choi and Kim sp. nov. Scale bars=0.25 mm.

Fig. 5.Pholcus pajuensis Lee, Choi and Kim sp. nov., male. A, B, left palp(A, prolateral view, B, retrolateral view); C, procursus tip, dorsal view; D, bulbal process, prolateral view.Abbreviations: e=embolus, pa =pseudo-appendix, pr=procursus, u=uncus. Scale bars=0.5 mm (A, B), 0.25mm (C, D).

Fig. 6. Pholcus pajuensis Lee, Choi and Kim sp. nov., female. A, epigyne, ventral view; B, internal genitalia, dorsal view. Abbreviation: pp=pore plate of internal genitalia. Scale bars=0.25mm.