Here is a spey shrimp tied with a little bit of uv materials. You can’t see them in normal light, jsut when you use your uv torch. Some say fish can’t see uv light, other say they have definitely more hook ups with flies tied with a bit of uv materials. I’ll let the fish decide… ;-)
Last but not least a Flatwing Tobis
You are showing fluorescence, not reflected UV wavelengths. The ultraviolet light upon striking the fluorescent materials instantly re-emits light in longer wavelengths that are visible to humans.
Trout, OTOH, can see solar light in the ultraviolet wavelengths between 350nm and 400nm, Those wavelengths increase in their percentage of available light at dusk and into the dark. This is the same time at which many of the best hatches and spinner falls occur. Mayflies, for example, use their ultraviolet vision to find the river and also have species and gender specific markings only visible in reflected ultraviolet wavelengths. Thus it makes sense to use materials for our flies that reflect UV in a manner appropriate to the UV markings of the insects the trout are consuming.
Fortunately, the dry flies that have stood the test of time already use natural materials with UV reflectance that is in harmony with the natural insects. (See http://www.overmywaders.com/cblog/index.php?/archives/112-Ultraviolet-Vision-in-Trout.html for supporting docs)