Saturday, September 1, 2007

Giant Texas Spider Web

This past week, there have been numerous stories about the Giant Texas Spider Web in Lake Tawakoni State Park such as this compiled CNN video re-posted on YouTube:

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There hasn't yet been a definitive identification of the species involved (stay tuned for more), but from the videos I have seen, the primary culprit looks to be a tetragnathid (long-jawed orbweaver) and not the assumed social spiders like Anelosimus spp. (doi:10.1111/j.1096-3642.2006.00213.x). This behaviour is rather unusual for a tetragnathid and reminds me of what was thought to be a mass dispersal event gone awry near McBride, British Columbia several years ago. In that case, the species involved were (in order of numerical dominance): Collinsia ksenia (Crosby & Bishop, 1928), Erigone aletris Crosby & Bishop, 1928, a Walckenaeria sp., and Araniella displicata (Hentz, 1847). See Robin Leech et al.'s article in The Canadian Arachnologist (PDF, 180kb). In the case of this massive Texas webbing, there also appear to be several other species present in the vicinity as evidenced by the nice clip of Argiope aurantia Lucas, 1833 in the YouTube video above.

Mike Quinn, who compiles "Texas Entomology", has a great page on the possible identity of the species involved in the giant web. The candidate in the running now is Tetragnatha guatamalensis O. P.-Cambridge, 1889, which has been collected from Wisconsin to Nova Scotia, south to Baja California, Florida, Panama, and the West Indies. The common habitat as is the case for most tetragnathids is on streamside or lakeside shrubs and tall herbs.

Another potential candidate (if these are indeed tetragnathids) is Tetragnatha elongata Walckenaer, 1842. I suspect the tetragnathids and A. aurantia are incidentals and not the primary culprits who made the giant mess of webbing. Since Robb Bennett and Ingi Agnarsson both have suspicions that the architect is Anelosimus studiosus (Hentz, 1850), and since it is highly unlikely it is a tetragnathid, I have my bets on ergionine linyphiids much like what happened in McBride, BC.

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