Cheiracanthium triviale ( Thorell, 1895 )

Esyunin, Sergei L. & Zamani, Alireza, 2020, ‘ Conundrum of esoterica’: on the long-forgotten genus Eutittha Thorell, 1878, with new taxonomic considerations in Cheiracanthium C. L. Koch, 1839 (Araneae: Cheiracanthiidae), Journal of Natural History (J. Nat. Hist.) 54 (19 - 20), pp. 1293-1323 : 1309

Cheiracanthium triviale ( Thorell, 1895)

Eutittha trivialis Thorell, 1895, p. 49 (description of ♀ from MYANMAR: 70 miles north of Eaugoon , Thayarwaddy; E. W. Oates leg. 1884–1887).

Chiracanthium trivialis (Sic!): Gravely 1931, p. 265, fig. 17 H in partim (♀ only; ♂ fig. 17 K, J–C. misidentified = rupicola ); Tikader & Biswas 1981, p. 71, figs 125–126 (♀); Majumder and Tikader 1991, p. 56, figs 103–108 (♂ ♀).

Cheiracanthium triviale: Dankittipakul and Beccaloni 2012 : fig. 16 (♀); Dhali et al. 2017, p. 49: figs 170–174, pl. 20 (♀).

Comments

Eutittha trivialis was originally described from Bago Division, Myanmar (= Burma) ( Thorell 1895). After studying a series of females from India, Gravely (1931) concluded that the female ‘varies in length from about 6–11 mm, the Gmatia and Madras specimens being much the smallest and one of the Kampong [East Himalayas] ones much the largest’ ( Gravely 1931, p. 265). However, Dankittipakul and Beccaloni (2012, p. 83) discovered that the ‘Himalayan form’ of C. triviale ( Thorell, 1895) illustrated by Gravely, was misidentified. It was actually the female of C. rupicolum . Also, they considered that ‘these two species are physically separated by different habitat where C. rupicolum has a clear preference for high altitude forests ( Burma: 1.200 –1.300 m a.s.l.; India, Darjeeling: 1.350 –1.500; China, Tibetan plateau)’ ( Dankittipakul and Beccaloni 2012, p. 83). The collection, which was examined by Gravely, also contained two males from the highlands of the Himalayas (‘in the Zoological Survey, 5000 ft., also in the Darjiling District’, cf. Gravely 1931, p. 265), which Gravely associated with C. triviale . In sum, the males described by Gravely actually refer to C. rupicola . An additional argument may be the following observation: we did not find differences in the structure of the male palp when we compared the illustration in Gravely (1931: fig. 17K) with those in Liu et al. (2019, Figs 1 (c) and 2(c)). However, Gravely’s figure differs from that depicted in Majumder and Tikader (1991: fig. 108) by the pointed apex of the dorsal tibial apophysis and the oval shape of the bulb.

Females of C. triviale are very similar to those of C. rupicola by the strongly convoluted copulatory ducts which form numerous loops. Therefore, both species significantly differ from E. insulana by this characteristic, as well as by the structural features of the male palp that are also characteristic of closely related species (for details see comments on C. rupicola ).

Figures

Figure 1. Eutittha insulana Thorell,1878, lectotype female.(a) Dorsal habitus.(b) Epigyne,ventral view. (c) Endogyne, dorsal view. Scale bars: a – 1 mm, b, c – 0.1 mm.