Falcileptoneta stilla, Oh & Lee, 2023

Oh, Jong-Hwa & Lee, Seunghwan, 2023, Six new epigean species of the genus Falcileptoneta Komatsu, 1970 (Araneae Leptonetidae) from South Korea, Zootaxa 5339 (1), pp. 40-58 : 51-54

Falcileptoneta stilla sp. nov.

Figures 9–10 , 13 (5)

Type material. Holotype: ♁, Gisan-ri , Gwangtan-myeon, Paju-si, Gyeonggi-do, Korea (37°46ʹ01.2ʺN, 126°55ʹ24.7ʺE), 18.iv.2020, J.W. Seo leg. ( NIBR) . Paratypes: 2 ♀, same data as holotype ( SNU) .

Etymology. The specific name is derived from Latin noun stilla meaning “drop of liquid” referring to the shape of ventral RTA.

Diagnosis. Falcileptoneta stilla sp. nov. can be separated from all Falcileptoneta species except F.baegunsanensis Xu, Kim, Yoo, Nam & Li, 2019 and F. boeunensis Seo, 2015 by the following combination: male palpal tibia with quadrangle RTA bearing two spines, palpal bulb with sickle-like embolus tip and three types of sclerite. Separated from F. baegunsanensis by having row of strong spines dorsally of the male palpal tibia (absent in F. baegensanensis ), and from F. boeunensis by having additional droplet-like RTA inwards (absent in F. boeunensis ) and with four dorsal spines of the male palpal tibia (five spines in F. boeunensis ).

Description. Male (Holotype). Habitus as in Fig. 9A, B . Total length 1.98. Prosoma brown with five setae in thoracic area, one in front of AER, and three around PME, 0.85 long 0.74 wide, 1.15 times longer than wide; eyes six well developed. Sternum semi-circular shield shape, 0.55 long, 0.50 wide. Endite L-shaped, longer than wide. Legs thin and slightly elongated, femur I 1.84 times longer than prosoma length, leg measurements: I (1.56, 0.30, -, -, -); II (1.36, 0.29, -, -, -); III missing; IV (1.54, -, -, -, -); palp 1.25 (0.48, 0.21, 0.30, 0.26). Palp ( Fig. 9C–F ): femur without row of strong spine; tibia with two trichobothrium, with four strong spines dorsally; retrolateral tibial apophysis (RTA) two, dorsal RTA quadrangle bearing two spines, ventral RTA droplet-shaped; tarsus unbranched, apically blunt with dense of setae apically; palpal bulb oval, 1.81 longer than wide, with black sickle-like developed embolus tip, and three types of sclerite: median sclerite narrow leaf-like, prolateral sclerite dark and short needle-like, retrolateral sclerite membranous. Opisthosoma light brown, plain and oval with scattered setae, 1.13 long, 0.69 wide.

Female. Habitus as in Fig. 10A, B . Similar to male in general appearance but slightly lighter than male in colouration. Total length 1.92. Prosoma brown with purplish border line in thoracic area, setae arrangement similar to male, 0.80 long 0.71 wide, 1.13 times longer than wide; eyes six. Sternum shield shape, 0.53 long, 0.51 wide. Legs thin and slightly elongated, femur I 1.86 times longer than prosoma length, leg measurements: I (1.49, 0.28, -, -, -); II 4.58 (1.30, 0.26, 1.32, 0.97, 0.73); III 3.74 (1.11, 0.24, 1.08, 0.87, 0.44); IV 5.17 (1.46, 0.26, 1.55, 1.14, 0.76); Palp 1.44 (0.45, 0.17, 0.35, 0.47). Internal genitalia ( Fig. 10C ): atrium subtriangular, spermathecae stalk loosely coiled downwards, spermathecae circular. Opisthosoma light brown, 1.12 long, 0.85 wide.

Habitat. This species was found in a layer of litter in mountainous regions.

Distribution. South Korea (Paju-si, Gyeonggi-do) ( Fig. 13 ).

Comments. DNA barcodes of this species have been reported in Oh et al. (2022), synonym to Falcileptoneta sp 13 (GenBank Acc. No.: ON041994, ON041995, ON041996).

Figures

FIGURE 9. Falcileptoneta stilla sp. nov., holotype male. A–B, habitus (A: dorsal view, B: ventral view); C–F, left palp (C: prolateral view, D: retrolateral view, E: dorsal view, F: ventral view). Abbreviations: Em=embolus, MS=median sclerite, PS=prolateral sclerite, RTA=retrolateral tibial apophysis. Scale bars: A–B=0.5 mm, C–F=0.1 mm.

FIGURE 10. Falcileptoneta stilla sp. nov., paratype female.A–B, habitus (A: dorsal view, B: ventral view); C, internal genitalia, dorsal view. Abbreviations: At=atrium, SH=spermathecae, SS=spermathecae stalk. Scale bars: A–B=0.5 mm, C=0.1 mm.

FIGURE 13. Sampling sites of collected specimens of six new Falcileptoneta species from Korea. 1 (Pink), F. alboclavata sp. nov.; 2 (Orange), F. decemspina sp. nov.; 3, (Brown) F. innuta sp. nov.; 4 (Yellow), F. jindoensis sp. nov.; 5 (Green), F. stilla sp. nov.; 6 (Blue), F. triformis sp. nov..