Five new species of the genera Falcileptoneta and Longileptoneta (Araneae, Leptonetidae) from South Korea

Abstract Five new leptonetid species belonging to Falcileptoneta Komatsu, 1970 and Longileptoneta Seo, 2015 are newly described from South Korea: F. dolsansp. nov. (Jeollanam-do), F. naejangsansp. nov. (Jeollabuk-do), L. buyongsansp. nov. (Chungcheongbuk-do), L. byeonsanbandosp. nov. (Jeollabuk-do) and L. jirisansp. nov. (Gyeongsangnam-do). All new species are found in leaf litter and described from both male and female specimens.


Introduction
The spider family Leptonetidae Simon, 1890 includes 22 genera and 363 species from North America, the Mediterranean region and Asia (Li 2020;Wang et al. 2020;WSC 2020). Members of the family are tiny (1-3 mm) and typically have six eyes, with the anterior four eyes in a recurved row, and the posterior two contiguous; some species have only four or two eyes or are eyeless (Seo 2016b). Most species live in secluded environments, such as irregular sheet webs in leaf litter, caves, or mines (Xu et al. 2019). In South Korea, there are 47 described species in four genera: Falcileptoneta Komatsu, 1970;Leptoneta Simon, 1872;Longileptoneta Seo, 2015and Masirana Kishida, 1942(WSC 2020. Falcileptoneta is a species-rich genus in the family Leptonetidae with 59 described species. The genus was erected by Komatsu (1970), with Leptoneta striata Oi, 1952 as the type species. Species of Falcileptoneta are mainly distributed in South Korea and Japan (Irie and Ono 2007). Among these, 23 species are found in South Korea (WSC 2020). Longileptoneta is a small genus in the family Leptonetidae with only 11 described species; 5 species are distributed in South Korea (WSC 2020). Longileptoneta was established by Seo (2015a) for a new species, L. songniensis Seo, 2015, and can be easily recognized by the strong spines restricted to the male palpal femur, the prolaterodistal spur and the prolateral curvature of the palpal tarsus (Seo 2016b). The aim of this paper is to describe two new species of the genus Falcileptoneta and three new species of the genus Longileptoneta from South Korea.

Materials and methods
All specimens were collected by hand from the litter layers of mixed forest in South Korea. Type material is deposited in the National Institute of Biological Resources (NIBR) in Incheon, South Korea. All specimens were preserved in 75% ethanol and examined under a Leica M205C stereomicroscope. Images were captured with an Olympus C7070 wide zoom digital camera (7.1 megapixels) mounted on a Leica M205C stereomicroscope and assembled using Helicon Focus 3.10.3 image stacking software (Khmelik et al. 2006). All measurements are in millimeters (mm). The left male palps are illustrated. Internal genitalia of females were removed and treated in lactic acid before illustration. Leg measurements are shown as: Total length (femur, patella, tibia, metatarsus, tarsus). The distribution map was generated with ArcView GIS 3.2 (ESRI 2002). Adobe Photoshop CC (Adobe Systems Incorporated) was used for digital editing of photos and maps. Terminology and taxonomic descriptions follow Wang et al. (2017) and Xu et al. (2019).  Seo, 2015 and F. geumsanensis Seo, 2016 but can be distinguished by the presence of three palpal tibial distal apo physes, dorsal apophysis sickle-shaped, middle apophysis black, triangular and ventral apophysis narrow and leaf-like ( Fig. 1D) (vs. dorsal apophysis long and spur-like, middle apophysis black and rugulose, and ventral apophysis finger-like in F. digitalis; dorsal apophysis beak-like, middle apophysis leaf-like and ventral apophysis spur-like in F. geumsanensis); and by the bulb with a spine-like prolateral sclerite ( Fig. 1C) Fig. 1A. Prosoma brown. Eyes six (Fig. 1A). Median groove, cervical grooves and radial furrows distinct. Opisthosoma brown, ovoid. Palp (Fig. 1C, D): femur without strong spine; tibia with three distal apophyses and one spine retrolaterally, dorsal apophysis sickle-shaped, middle apophysis black, triangular, ventral apophysis narrow, leaf-like (Fig. 1D), and with one strong dorsal spur (Fig. 1C, D); tarsus with transverse depression (Fig. 1D). Bulb with embolus bearing sickle-like tip and three types of sclerites: prolateral sclerite spine-like; median sclerite shoe horn-like; retrolateral sclerite transparent and membranous ( Fig. 1B-D).
Female (paratype). Similar to male in color and general features, habitus as in Fig.  4A (Fig. 4C) with atrium rectangular, genital duct coiled apically, and spermathecae round.
Etymology. The specific name refers to the type locality and is a noun in apposition.
Female (one of the paratypes). Similar to male in color and general features, habitus as in Fig. 6A   Diagnosis. Longileptoneta byeonsanbando sp. nov. is similar to L. gayaensis Seo, 2016 and L. jangseongensis Seo, 2016 but can be distinguished by the palpal tibia with one distal columnar apophysis, with apophysis tip armed with one long spine retrolaterally (Figs 7D, 8B) (vs. tibia without apophysis in L. gayaensis; tibia with one small apophysis armed with one spine in L. jangseongensis); by the palpal bulb with narrow, leaf-like prolateral sclerite and ribbon-like median sclerite (Fig. 7B-D) (vs. needle-like prolateral sclerite and shoehorn-like median sclerite in L. gayaensis; without prolateral sclerite and leaf-like median sclerite in L. jangseongensis); and can be further distinguished from L. gayaensis by the presence of two spurs at tarsal tip (Fig. 8A, B) Fig. 7A. Prosoma brown. Eyes six (Fig. 7A). Median groove, cervical grooves and radial furrows distinct. Opisthosoma brown, ovoid. Palp (Figs 7C, D, 8A, B): femur with many strong spines and very long (Fig. 8A, B); patella very long (Fig. 8A, B); tibia with one distal columnar apophysis, with apophysis tip armed with one long spine retrolaterally (Figs 7D, 8B); tarsus with two spurs at tip and many spines, and with prolateral curvature (Fig. 8A, B). Bulb with leaf-like embolus and three types of sclerites: prolateral sclerite narrow, leaf-like; median sclerite ribbon-like; retrolateral sclerite with serrated tip, transparent and tongue-like ( Fig. 7B-D).
Etymology. The specific name refers to the type locality and is a noun in apposition.
Female (paratype). Similar to male in color and general features, habitus as in Fig.  11A 11C) with atrium trapezoidal, spermatheca and genital duct tube-shaped, loosely coiled.
Etymology. The specific name refers to the type locality and is a noun in apposition.