Bioacoustics of Cheiracanthium insigne

Remarks. Thorell (1895: 47) gave a formal description of a single male spider collected from Tharrawaddy followed by the description of a single female from Rangoon ( Thorell 1895: 48 ) as E. gracilipes in his Descriptive Catalogue of the Spiders of Burma . No significant differences were detected between the male types of C. insigne and that of E. gracilipes Thorell, 1895 . Therefore, we propose a formal synonymy, Eutittha gracilipes as a junior synonym of C. insigne O . P.– Cambridge, 1874 . Our study of the types and additional material indicates that all males of this species ( Figs 1, 3–7 ) have narrow and very long tegular flanges that are semi-transparent, extending prolaterally and posteriorly; the ribbon-shaped embolus is elongated and runs along the margin of the tegular flange; the tegular apophysis is absent; the baso-retrolateral spur on the cymbium is short and triangular. As for the female of E. gracilipes , Thorell provided the following remark ‘Si propriae speciei est haec femina, E. truncata appelletur’ (‘If this female is a species of its own, then it should be called E. truncata ’). Thus, Thorell was not convinced that both specimens belong together in the same species, but he had considered the possibility and therefore added this particular remark. Unlike the male of E. gracilipes , the female type does not resemble that of C. insigne . Consequently, it cannot be synonymized with latter species. It was considered a separated species from E. gracilipes and the name truncata is proposed (see below). According to the ICZN (2000) article 12.1 the name E. truncata is available as it satisfies the requirements: it has been accompanied by a description. The identity of the C. insigne females is problematic. O . P.–Cambridge mentioned in the species description that ‘the genital aperture is small and of a narrow transverse kidney-shape’. He also provided an illustration of the epigynal area of the female syntype ( O . P.– Cambridge 1874 ; fig. 32b). This illustration together with an original description is the only reliable source of information on the female. Later, Gravely (1931; fig. 17M) provided an illustration of the epigyne of C. insigne , which is quite similar to that of E. truncata , but it bears little resemblance to that of C.insigne made by O . P.–Cambridge. Gravely (1931: 266) stated that ‘the only female [of Eutittha ] in the collection is the one lent by the British Museum from Rangoon’ so the female syntype of C. insigne was apparently not available at the time he received material from the NHML. It comes as no surprise when Gravely ‘find no satisfactory distinction between E. gracilipes from Burma and C. insigne from India [on the basis of the male palpal morphology. See also Gravely 1931 : fig. 17L]’ and ‘all should be united into a single species’. The illustration of female C. insigne in Gravely’s work was undoubtedly based on the type of E. truncata from Rangoon on an assumption that E. truncata is a true conspecific female of C. insigne , being unaware of the significant differences between the female genitalia of these two species. The result of incorrect matching of the conspecific sexes is very obvious: although males of C. insigne were subsequently collected and illustrated several times, no record of a female was documented i.e., Tikader & Biswas (1981; male only) , Chen & Zhang (1991; male only) , Majumder & Tikader (1991; male only) , Song, Zhu & Chen (1999 ; male only). O . P.–Cambridge clearly mentioned that the type series of C. insigne was made from the Bombay Collection presented to the museum by Major J. Hobson and from the Ceylon Collection by G. H. K. Thwaites, whose collections provided ‘many adult examples of both sexes’. Although the original description does not specify the number of specimens examined, it implies there was a good type series present. Unfortunately, only a single male labelled C. insigne remains in NHML. We were unable to locate the female syntype in the collection of NHML and it is presumably lost (see discussion below). The male is accompanied by a label written by Reginald Innes Pocock, who wrote many other type labels in the NHML’s collections ( Figs 2 vs. 8). The label does not provide any indication of the type status. This renders the taxonomic status of the designated female C. insigne even more doubtful. Correct identification can be made only after adults of both sexes are collected at the same time from the type localities, particularly from Sri Lanka and India .