A survey of some Odonata for ultraviolet patterns

A series of museum specimens comprising 338 spp. in 118 genera and 16 families were photographed both with and without a Kodak 18-A ultraviolet (UV) filter. These photographs revealed that only Euphaea amphicyana reflected UV from its wings whereas all other spp. either did not absorb UV (e.g. 94.5% of the Coenagrionidae) or did so to varying degrees. In particular, spp. with flavescent. orange or brown wings (or wing patches) exhibited UV absorption for these same areas. However, other spp. with nearly transparent wings (especially certain Gomphidae) also had strong UV absorption. Pruinose body regions reflected UV but the standard acetone treatment for color preservation dissolves the wax particles of the pruinosity and destroys UV reflectivity. As is typical for arthropod cuticle, non-pruinose body regions absorbed UV and this obscured whatever color patterns might otherwise be visible without the camera’s UV filter. Frequently there is sexual dimorphism in UV patterns (wings and body) and these differences may play a role in various aspects of mating behavior.