EPOW - Ecology Picture of the Week

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Spider of the Sheeted Web

Credit & Copyright:  Dr. Bruce G. Marcot
  

Explanation:  We discovered this hanging predator in the dark of night, in the native woods of Pureora Forest Park, North Island, New Zealand.  Here hangs a sheetweb spider, so named for ... well, for obvious reasons. Sheetweb spiders -- family Stiphidiidae -- are found only in New Zealand, and consist of 13 genera, including this one, genus Cambridgea, of which 31 species have been described.   We are fortunate to observe this arachnid, as sheetweb spiders are generally nocturnal and hide during the day.  Though it looks formidable, sheetweb spiders are mostly harmless (to humans, not to their insect prey!) and bites seem to be rare.   Sheetweb spiders typically hang inverted as shown in these photos, waiting for some unwary insect to fall onto their web, at which point the spider dispatches their prey by biting through the web.  During the day, sheetweb spiders hide in a tunnel created by their web, only to emerge after dark.      Here, a fuller section of the chaotic sheeted web can be seen, lashed against the trunk of a tree and to various strands of dried Lycopodium (clubmoss).