Yunohamella varietas, Lee & Kim, 2021

Lee, Sue Yeon & Kim, Seung Tae, 2021, A New Spider of the Genus Yunohamella (Araneae: Theridiidae) from Korea, Species Diversity 26 (2), pp. 165-169 : 165-168

Genus Yunohamella Yoshida, 2007 Yunohamella varietas sp. n. ( Fig. 3 )

Type materials. Holotype: male, 11 August 2020, Jikdong-ri , Sangnam-myeon , Eonyang-eup, Ulsan Metropolitan City, Korea (35°34′86.0″N, 129°07′91.1″E) . Paratype: one male, same data as the holotype, collected by S . T. Kim.

Etymology. The species name is derived from the Latin noun ‘ varietas ’ meaning mottled appearance, referring to the black and whitely mottled pattern on dorsum of the abdomen.

Diagnosis. The new species is similar to Y. lyrica and Y. serpatusa with important diagnostic characters of the genus in the genital structure such as the shape of embolus, conductor, median apophysis of the palpal organ in morphology. The new species with dorsal spots with a cardiac pattern on the abdomen, embolus long and slightly curved, thick and long beak-like conductor, peach-like median apophysis ( Fig. 3F ), but can be easily distinguished from Y. lyrica with a distinct dorsal stripe on the abdomen, embolus medium and straight, long and flame-like conductor with a twisted tip, angular median apophysis ( Fig. 4A ) ( Levi 1957: 89, figs 322, 323; Yoshida 1987: 13, figs 1, 2; Namkung 2002: 96, figs 13, 14b) and from Y. serpatusa with a distinct dorsal stripe on the abdomen, embolus short and straight, broad and long spatula-like conductor, round median apophysis ( Fig. 4B ) ( Zhu et al. 1993: 92, figs 14–17; Marusik and Logunov 2017: 92, figs 35–39).

Description. Male holotype. Total length 3.03 (habitus). Carapace: 1.15 long/0.93 wide, dusky yellowish brown, the head region infuscate, thoracic margin with a broad blackish gray band, suboval, cervical and radial furrows indistinct, longitudinal fovea V-shaped and deeply depressed, head region slightly elevated ( Fig. 3A ). Eyes: AER 0.49, PER 0.54, AME 0.11, ALE 0.08, PME 0.10, PLE 0.12, AME- AME 0.10, AME-ALE 0.04, PME-PME 0.06, PME-PLE 0.05, AME-PME 0.09, ALE-PLE contiguous, all eyes on slightly raised eye tubercles, PMEs encircled with black, AER recurved and PER almost straight from above ( Fig. 3B ). Chelicera: 0.60 long/0.21 wide, yellowish brown with one promarginal tooth and 2 retromarginal teeth ( Fig. 3C ). Endite: 0.30 long/0.15 wide, dusky and pale blackish brown. Labium: 0.13 long/0.22 wide, dusky and pale blackish brown. Sternum: 0.64 long/0.62 wide, blackish brown, anteromedian part light, triangular, convex, posterior end blunt protruding deeply between the coxae of leg IV ( Fig. 3D ). Legs: I 9.89 (2.97, 2.98, 2.90, 1.04)/II 4.98 (1.95, 1.30, 1.08, 0.65)/III 3.19 (1.06, 0.85, 0.77, 0.51)/IV 4.95 (1.70, 1.36, 1.30, 0.59), leg formula I–II–IV–III, pale yellowish brown, long and slen- der, median and distal end of femur with blackish brown annuli, distal ends of tibia and metatarsus with blackish brown annuli. Abdomen: 1.28 long/0.97 wide, pale grayish brown, ovoid, cardiac pattern present, dorsum with paired black and white spots, clothed sparsely with long reddish brown hairs ( Fig. 3A ). Palp: 1.02 (0.43, 0.23, –, 0.36), palpal bulb almost globular, tegulum large, thick embolus almost straight and slightly curved with a broad base and pointed tip originated from median part of the tegulum, broad beaklike conductor conjugated with tegulum and originated from the anteromedian part, seminal duct crooked repeatedly and characteristic, median apophysis large and peach- shaped, subtegulum distinct ( Fig. 3E–H ).

Female. unknown.

Distribution. Korea (Jikdong-ri, Ulsan Metropolitan City) ( Fig. 1).

Remarks. The present new species was collected between rice plants with a sweep net and first reported in rice fields ( Fig. 1A). A total of seven species of spiders belonging to the genus Yunohamella have been described, and most of the species in the genus have been found in various types of forests to date: Y. gibbosa Gao and Li, 2014 from tropical seasonal rainforests ( Gao and Li 2014), Y. lyrica from Magnolia baillonii Pierre (Magnoliaceae) plantation (20 years old plantation), mountains, or hillock forests ( Gao and Li 2014; Kim et al. 2016), Y. palmgreni (Marusik and Tsellarius, 1986) from various type of forests and trees ( Blick et al. 2006), Y. serpatusa from the giant forest or Mongolian oak forest ( Quercus mongolica Fisch. ex Ledeb. , Fagaceae ) ( Zhu et al. 1993; Seo 2015), Y. subadulta from mountains or hillock forests ( Kim et al. 2016), Y. takasukai Yoshida, 2012 from mountain forests ( Yoshida 2012) and Y. yunohamensis from the entrance of caves and mountain forests ( Chikuni 1989; Namkung 2002). All four species of the genus reported in Korea have only been found in forest habitats so far. Only two males of Y. varietas sp. n. were collected in rice fields during 2016–2020. We regularly investigated the rice fields where males were captured and conducted a forest survey near the rice fields for collecting this female species. However, the female eventually was not collected. This may be due to the survey period being inconsistent with the seasonal occurrence of females, or their main habitat being further away from our survey site. Generally, adult female spiders are less mobile and more likely to stay in the same place for longer periods than males do. On the other hand, males are more active and dispersive than females ( Foelix 1996). Considering the congener’s habitat and records of Korean rice field spiders, this species is unreasonable to classified as a typical rice field spider. It seems to be accidently introduced into rice fields through ballooning after maturity from an adjacent hillock forest ( Fig. 2A, B ).

Figures

Fig. 3. Yunohamella varietas sp. n., male holotype. A, Body (habitus in specimen), dorsal view; B, eye region, from above; C, chelicera (left), retrolateral view; D, sternum; E, palp (left), prolateral view; F, ditto, ventral view; G, ditto, retrolateral view; H, ditto, dorsal view (C, conductor; E, embolus; Ma, median apophysis; Sd, sperm duct; St, subtegulum; T, tegulum). Scale bars in mm.

Fig. 4. Palp (left), ventral view; Yunohamella lyrica (Walckenaer, 1841) from Inje-gun, Gangwon-do, Korea (A) and Yunohamella serpatusa (Guan and Zhu in Zhu et al., 1993) from Pyeongchang-gun, Gangwon-do, Korea (B). (C, conductor; E, embolus; Ma, median apophysis; Sd, sperm duct; St, subtegulum; T, tegulum). Scale bar in mm.

Fig. 2. Collection site of Yunohamella varietas sp. n. (A) and various types of hillock forests adjacent to the rice fields (B).