Trichonephila clavata (L. Koch, 1878 )

Fomichev, A. A. & Omelko, M. M., 2024, NEW FOR THE ASIAN PART OF RUSSIA TAXA OF SPIDERS (ARACHNIDA: ARANEI), Far Eastern Entomologist 502, pp. 12-20 : 13-16

Trichonephila clavata (L. Koch, 1878)

Figs 1–5

Nephila clavata Koch, 1878: 741 , pl. 15, f. 4 (♀); Bösenberg & Strand, 1906: 190, pl. 3, f. 11, pl. 11, f. 217 (♂ ♀).

Trichonephila clavata Kuntner et al., 2019: 557 .

MATERIAL EXAMINED. Russia: Primorsky krai, Vladivostok, Botanical Garden- Insitute , 43°13’23.22’’N, 131°59’53.61’’E, webs on trees, 90 m, 1.X 2023, 1♀, 1♀ juv., M.M. Omelko ( FEFU) .

DIAGNOSIS. Three species of Trichonephila are known to occur in Asia: T. antipodiana (Walckenaer, 1841) , T. clavata , and T. plumipes (Latreille, 1804) . These entire species exhibit relatively similar copulatory organs but are well-distinguished by their external morphology. Males of T. clavata can be easily differed from those of T. antipodiana by the coloration of the abdomen and carapace with pattern (vs. uniformly colored; cf. Namkung, 2003: fig. 18 and Harvey et al., 2007: figs. 3, 6). It also differs from T. plumipes in having a smooth tip of the conductor (vs. with subdistal triangular protuberance; cf. Yin et al., 2012: fig. 217d and Harvey et al., 2007: fig. 39). Females of T. clavata can be easily distinguished from females of both other Asian species by the coloration of the dorsal surface of the abdomen, featuring alternating bright yellow and gray transverse stripes (vs. without transverse stripes; cf. Harvey et al., 2007: figs 3, 6, 8).

REDESCRIPTION. Female. Total length 24.20. Carapace: 8.49 long, 5.85 wide. Abdomen: 21.54 long, 10.76 wide. Coloration. Carapace almost black with dark brown median part and head area, lateral bands yellow, humps ascent. Chelicerae, labium and endites almost black. Sternum black with three yellow spots anteriorly and yellow stripe posteriorly. Palps: Fe–Ti yellow, Ta brown. Legs: Fe I–II black with yellow ring medially and yellow stripe ventro-proximally, Fe III–IV yellow with black ring medially and black distally; Pa I–IV black; Ti I–IV black with yellow ring medially; Mt I–IV black, yellow proximally; Ta I–IV black. Abdomen dorsally with alternating bright yellow and gray transverse stripes; lateral sides with stripes extending from dorsal surface and two large red spots posteriorly, ventral surface yellow with black irregular spots and red spot posteriorly, next to spinnerets. Spinnerets black. Eye sizes and interdistances: AME 0.27, ALE 0.24, PME 0.27, PLE 0.25; AME–AME 0.42, AME–ALE 0.85, PME–PME 0.46, PME–PLE 0.92, AME–PME 0.50, ALE–PLE 0.22. Clypeus height at AME 0.13. Chelicerae with 3 promarginal and 3 retromarginal teeth. Legs and palp measurements: Palp: 8.63 (2.72, 1.32, 1.53, -, 3.06); I: 52.27 (14.83, 3.27, 12.88, 17.96, 3.33); II: 43.69 (12.82, 3.07, 10.07, 14.61, 3.12); III: 22.21 (7.25, 1.81, 4.02, 6.99, 2.14); IV: 36.82 (12.51, 2.11, 7.39, 12.15, 2.66).

Epigyne as in Figs 3–4 . Epigyne almost black, barely visible on the abdomen, twice wider than long, posterior margin slightly concaved. Receptacles (Re) large, round (right receptacle of studied specimen underdeveloped).

DISTRIBUTION. Widely distributed in East, Southeast and South Asia, from India to Japan and Russia ( Fig. 13 ).

REMARKS. The discovery of T. clavata in the Russian Far East represents one of the most northernmost records for this species, genus and subfamily Nephilinae in general. The closest known localities are in South Korea (ca. 650 kilometers to the south) and in Japan (ca. 500 km to the northeast). Both these locations have considerably warmer climate than southern part of the Russian Far East. On the one hand, this shift in the distribution range can be attributed to the overall climate warming in the region. On the other hand, the find of T. clavata in the Botanical Garden of Vladivostok can be explained by unintentional introduction with seedlings. Finally, there may be another reason. Nephilinae are known to have the ability to spread over vast distances using ballooning ( Lee et al., 2015). In any case, Nephilinae have a high dispersal ability both with the help of people and independently. It is important to note that exactly T. clavata in recent years was introduced to USA, where it subsequently spread relatively widely ( Hoebeke et al., 2015).

Family Zoropsidae Bertkau, 1882

REMARKS. Zoropsidae is a relatively small spider family with 180 extant species belonging to 27 genera distributed almost worldwide (WSC, 2024) but only three are found in the Palaearctic region: Akamasia Bosselaers, 2002 , Takeoa , and Zoropsis Simon, 1878 . The former genus is endemic to Cyprus ( Bosselaers, 1997). Two centers of diversity are known for Zoropsis . Most species are described from the Mediterranean and another hotspot of diversity is China ( Li et al., 2015; Wang et al., 2020). Only one species, Z. kirghizicus Ovtchinnikov et Zonstein, 2001 , is known from Central Asia ( Ovtchinnikov & Zonstein, 2001). However, this species may belong to an undescribed genus judging by the unique very broad and deeply concave retrolateral tibial apophysis and the scape almost reaching the epigastral grove. Here the family Zoropsidae is recorded for the Russian Far East for the first time.

Genus Takeoa Lehtinen, 1967

REMARKS. Takeoa is represented by four species distributed in East Asia ( Tang et al.,

2004). This genus is new for the fauna of the Russian Far East.

Figures

Figs 1–5. Trichonephila clavata. 1– body, dorsal view; 2 – same, ventral view; 3 – epigyne, dorsal view; 4 – same, ventral view; 5 – living specimen. Abbreviation: Re – receptacle. Scale bars = 5 mm (1, 2), 0.2 mm (3, 4).

Fig. 13. Distribution map of Trichonephila clavata. Red square – new record, black squares – previous records, black squares with question marks – records without precise location.