Meeting Abstract
The bella moth Utetheisa ornatrix (Lepidoptera:Arctiidae) sequesters pyrrolizidine alkaloids from host plants during its larval stage. Adults are diurnal, and previous studies have suggested that they visually signal their distastefulness to predators by means of conspicuous coloration. However, the wing patterns that give rise to this aposematic signal are exceptionally diverse within the species and remain understudied. Both the background color, and specific pattern elements of the dorsal surface of forewings vary enormously within local populations, ranging from brilliant high-contrast red, black and white, to an almost pure overall white. Using animals from a laboratory colony, we documented and quantified the range of variation in U. ornatrix wing patterns using spectrophotometry, and techniques from geometric morphometrics. To identify the genetic correlates of color pattern variation, we conducted a series of selective breeding experiments. In addition, the environmental contributions to wing patterns were studied by varying the conditions under which animals develop. Given that aposematic signals tend to be more effective when animals converge on a common phenotype, the fact that there is so much variation in U. ornatrix wing patterns is puzzling. We conclude by developing an evolutionary hypothesis which suggests that this kind of pattern polymorphism can be advantageous to aposematic organisms when dishonest signaling is possible.
