Thursday, June 11, 2009

Spider Web reflects UV to attract prey

Another find: I was reading some time ago a paper that spider webs would actually reflect ultraviolet (UV) light, so as to attract prey (insects like bees etc). Well it just happened that I found a web in one corner of my balcony, so why not using my "bee vision" filter XBV2 take some shots and test it out?

[click on image yields a larger one]

Spider web tetrachromatic shot (UV+B+G+R) using XBV2 filter:


and now the proof that it actually only reflects UV+Blue light be taking away these two channels and just showing the Red and Green channel, which hardly shows anything of that web:


But the UV+Blue only (without G+R) makes it pretty obvious that the web is indeed pretty visible in ultraviolet light!



I just wonder how nature accomplishes that, to attract insects using a high UV reflection of that web and at the same time scare away birds which may pick the captured prey away and destroy the web?

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos