I have heard that if you paint the ceiling of your porch blue, it resembles the sky and wasps will not build there.

Hi Jay,

Huh, never heard that before, it does sound like one of those urban legends to me though already. I say that as the visual system of wasps is really poorly known, and scientists have only really known about the vision of closely related honeybees in about the last 15 years.

The reason i am going to doubt the reality of this, is that all insects including bees, wasps and ants, all see colours completely differently than we do. So, though we see the sky as blue, we humans see colour using a combination of three major receptors, called opsins, one optimised for red, another for green, and a third for blue. theres also a forth called rhodopsin, really which only works in dim light (ie when there is not enough light around for the others, and we cant see colour). What we see as blue in the sky, or in paint, is really more of our blue receptor responding to light bouncing of the paint (or bouncing off dust in the sky). The other opsin receptors in our eyes also respond to this light, but not so strongly, nor in such large proportions as the blue-optimised receptors do.

Now, insects like honeybees are known to have three receptors, other insects have more, some types have less. Honeybees have a receptor optimised for blue also, another for greenish light, but their third type is for UV light. That is light in part of the spectrum we cant see as none of our receptors is sensitive enough to it. And this receptor is the main reason i would suggest that insects see blue paint in a totally different way to the sky ... the sky has ultraviolet patterns in it caused by clouds, dust and magnetism, that will make sense to insects, some of which they use for navigation,e.g. lines in the sky that they may use to direct them which way is north. The paint should be one flat colour, which may or may not have any UV signals (depending on its components), but more importantly not necesarily interpreted by the insects as the same base color as they see the sky..

 Ok, sorry... not an easy answer. In short, insects see 'blue' in a totally different way than we humans do, so they probably wont be fooled so easily !!