Caught this image of a web in my orange tree, seems to be acting like a simple spectrograph, the picture is unaltered straight of the camera (the raw file has a lot more detail). looks a bit like the images you guys post here (sort of). Anyway thought some here might it interesting.
Now if we could train the spider to walk back and forth about 200 times, you may have a very nice diffraction grating there!
Much cheaper than a sophisticated ruling engine.....