When it comes to spiders, most species are nocturnal. However some species such as the jump spider or the garden orb weaver are diurnal. During their evolutionary history, some species of spiders have even changed from a nocturnal lifestyle to a diurnal lifestyle. The important change in their environment was irradiation by sunlight. Orb webs of diurnal spiders may be affected by exposure to ultraviolet irradiation whereas those of nocturnal species may be unaffected.
The effects UV rays have on the mechanical properties of spider silks is something that should be seriously considered. The webs of orb weaving spiders must trap insect prey, which closely relates to the breaking energy of the spider silk constituting the orb webs.