Vibrating Spiders - Family Pholcidae
Also commonly known as daddy longlegs spiders, cellar spiders
Species: Pholcus phalangioides (Fuesslin, 1775)
Live adult spiders and spider eggs photographed indoors at Winfield, Illinois, USA.


Male vibrating spider, also known as cellar spider or daddy longlegs spider

Quicktime Movie of Vibrating spider vibrating (1.8 Mb)
 


Spider Eggs


vibrating spider - male

The vibrating spider is also commonly called the daddy longlegs spider, after its ... what? Guess. I found this specimen living in close proximity to Steatoda  cobweb spiders in my garage. These spiders probably prey upon each other when the pickings get slim in the wintertime, but as of September, there are still enough flying insects visiting for all to coexist peacefully. It is said these spiders, when threatened, vibrate their legs and bodies so rapidly as to become invisible; hence their other common name: vibrating spider. Actually, what they do is, spin themselves in a small circle so rapidly they become nearly invisible; that is the ones I've seen in my father's cellar do this. The quicktime movie link shows one of these spiders exhibiting this behavior - it's really quite a sight!

There is another, more famous old wives' tale about this family of spiders: that their bite is the most dangerous, or their venom is the most lethal known to man. Of course, that's rubbish. These spiders have not the equipment for delivery of any but the tiniest amounts of venom, and that dangerous only to the smallest of creatures, flies and other spiders, etc. People love to be afraid of spiders, especially ones that like to live where we live, but these guys are completely harmless, even beneficial. (I don't tolerate then in my actual living space, but the garage is ok although I do tire of sweeping up the insect bits and pieces they are constantly dropping on the floor after meals.)

 

              
 
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