Spiders of the genus Tetragnatha (araneae, tetragnathidae) in the Society Islands

This study revises the status of knowledge of the spider fauna of the Society Islands. Until recently, the literature on the spider fauna in these islands has suggested that the genus Tetragnatha in particular is noticeable for its poor representation in comparison with the large radiation in the Hawaiian Islands. Expeditions were conducted to determine whether this genus is indeed poorly represented in the islands as the literature would suggest. The results indicate that the islands actually have a number of endemic Tetragnatha, although there is no noticeable adaptive radiation as is seen in the Hawaiian Islands. Results of field expeditions in 1999-2000 and studies on historical collections have shown that: (1) Reports of the cosmotropical species T. mandibulata in the Society Islands are probably not valid; these were misidentifications for either T. macilenta or T. nitens. (2) Tetragnatha huahinensis is a synonym of T. macilenta. (3) There are three new species of Tetragnatha, all of which are described here and appear to be endemic to middle and high elevations of the Society Islands (from Tahiti, Moorea and Raiatea). In total, there are six species of Tetragnatha in the Society Islands: in addition to the three endemic species there is one possibly indigenous (T. macilenta), and two that may be of more recent introduction (T. nitens and T. maxillosa).