The effects of UV reflectance on mate searching in Enallagma carunculatum

Natural History & EvolutionSeveral studies on damselflies have examined potential causes for female-limited polymorphisms and how males distinguish between the morphs. Recent spectral analyses have shown that in some species, such as Enallagma carunculatum, the blue morph reflects ultraviolet wavelengths, like males, whereas the green morph does not. Therefore, UV reflectance may be a visual cue used by mate-searching males to detect females. Our study gauged male reaction toward blue females modified with sunscreen to decrease UV reflectance, blue female controls, green female controls, male controls, and UV-modified males. Blue female controls had many more sexual reactions than any other control treatment. UV females and male controls experienced some reactions. From this we speculated that males use multiple visual cues, including coloration pattern and hue as well as UV reflectance. Female variation within these traits suggests that female morphs have evolved in response to other female morphs and not as male mimics.http://deepblue.lib.umich.edu/bitstream/2027.42/57473/1/Hatchew_Kim_Sheu_2007.pd