Eutittha insulana Thorell, 1878

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 : 1299-1300

Eutittha insulana Thorell, 1878 , comb. nov. Figs 1a–c , 2b

Eutittha insulana Thorell, 1878, p. 179 (description of lectotype ♀ and paralectotype juvenile ♀ (both designated here) from INDONESIA: Maluku Islands: Ambon Island (03°38 ʹ 17 ″ S, 128°07 ʹ 02 ″ E); O. Beccari leg. 1872–1877). Simon 1897, p. 87 (formal transfer to Cheiracanthium , here rejected.)

Comments

Eutittha insulana is the type of the genus. In the taxonomic remarks for ‘ Cheiracanthium insulanum ’, Deeleman-Reinhold (2001, p. 231) noted that ‘the specimens from West Thailand agree fully with those from the Moluccas [= Maluku Islands – type locality of E. insulana ], and appear to be conspecific’. Our study of the syntypes of E. insulana (deposited in MCSNG) revealed that this statement is erroneous. The female lectotype of E. insulana significantly differs from the females described by Deeleman-Reinhold under C. insu /anum (see comments on C. adjacensoides Song, Chen & Hou, 1990 for details). Thus, currently, this species is reliably known only by one female and one immature female, originally described from Ambon Island, Indonesia ( Thorell 1878).

The female of E. insulana is very close to that of E. marplesi , described from New Guinea, by the structure of the epigyne. Both species are characterised by epigyne with transverse atrium and two ventrally visible loops of copulatory ducts ( Figures 1 (b)). However, E. insulana is 2 times smaller than E. marplesi (but carapace of E. insulana is 1.6 times shorter than that of E. marplesi ) and appears to have a different colour: carapace and chelicerae appear to be solid yellowish brown ( Figure 1 (a); dark yellow or brick after Thorell (1878)) in E. insulana , while carapace is two-toned in E. marplesi : the thoracic part of carapace yellow, the cephalic part and chelicerae orange ( Chrysanthus 1967).

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.

Figure 2. Epigyne and endogyne of Eutittha mordax (L. Koch, 1866) and E. insulana Thorell, 1878. a. E. mordax epigyne, ventral view. b. E. insulana endogyne, dorsal view. Abbreviations: AR – anterior rim; CD – copulatory duct; S – spermathecae. Scale bar: g 0.1 mm.