ARGYRODINAE

Agnarsson, Ingi, 2004, Morphological phylogeny of cobweb spiders and their relatives (Araneae, Araneoidea, Theridiidae), Zoological Journal of the Linnean Society 141 (4), pp. 447-626 : 476-477

ARGYRODINAE

I support Yoshida’s (2001b) elevation of ‘ Argyrodes ’ sensu Exline & Levi (1962) and Levi & Levi (1962) to subfamily level, Argyrodinae , based on Simon’s (1894) tribe name Argyrodeae (see also Arnedo et al., 2004). Ariamnes , Rhomphaea and Spheropistha are very likely monophyletic, but render the remaining ‘ Argyrodes ’ paraphyletic ( Fig. 102 ). The informal ‘generic groups’ Faiditus ( A. cancellatus and A. cordillera groups) and Neospintharus ( A. trigonum group) are therefore again recognized as genera. Although monophyletic, Exline & Levi’s ‘ Argyrodes ’ includes so much diversity and so many distinct groups, that clarity, increased information content, ease of information retrieval and communication, demand its division. Few theridiid genera are as readily diagnosable and recognizable as these five argyrodines, even after a superficial examination of somatic characteristics. Exline & Levi (1962) explicitly rejected the monophyly of these Argyrodes components, but this study has uncovered numerous synapomorphies that define each group (see below) and appear uniformly distributed amongst their members (pers. observ.).

The phylogeny presented here only explicitly tests one of the new circumscriptions, Argyrodes s.s. To test the monophyly of the other argyrodine genera I ran a preliminary analysis adding Ariamnes sp. , Faiditus ululans , Neospintharus concisus and Rhomphaea projiciens to the data matrix (see Table 4). The results (single most parsimonious tree: L = 759, CI = 0.37, RI = 0.75, not shown) support the monophyly of all argyrodine genera included here and are otherwise identical to the mpt of the core matrix. A more detailed analysis, adding other putative generic synapomorphies, as well as further character information, e.g. details of the palpal organs so characteristic of each group, is likely to further support this result. The modified data matrix is available at http:// www.gwu.edu/~spiders/cladograms.htm.

Morphological observations (sorting through hundreds of argyrodines of all five genera, from all over the world), as well as behavioural data (I. Agnarsson, unpubl. data), further support the validity of all these groups. Furthermore, 2–7 species of each genus (see specimens examined, Appendix 3) were examined using light microscopy to verify the presence of putative generic synapomorphies. The diagnosis offered here for each genus is preliminary and speculative with regard to the features that require SEM to verify their presence (or absence). These features have been examined only in the species in the core matrix, and examining in such detail all the>230 argyrodine species is clearly outside the scope of this study. However, I also explicitly propose putative synapomorphies of all genera that have been verified in other species examined in detail (see Appendix 3), and synapomorphies based on conspicuous somatic characters, evident in even superficial examination of specimens, and from species descriptions and drawings. These putative generic synapomorphies appear highly consistent.

Full transfer of all valid species currently in Argyrodes is a task that cannot be attempted here. However, based on Exline & Levi (1962) and González & Carmen (1996), species groups (and descriptions) of the vast majority of New World Argyrodes can be correctly placed. Zhu’s (1998) work, likewise, allows the placement of Chinese species. Furthermore, species are transferred to Rhomphaea and Ariamnes if originally described in those genera, and later work has not contradicted this placement. The remaining species must remain in Argyrodes for the time being.

Figures

Figure 102. Single most parsimonious cladogram (L = 759, CI = 37, RI = 73) and preferred phylogenetic hypothesis of theridiid spiders with major groups identified and the family Theridiidae shown with thick lines. Numbers above branches indicate Bremer support; below branches are bootstrap values (above 50%). Parsimony jackknife scores were nearly identical and are not shown.