Expanding the nymphalid groundplan's domain of applicability: Pattern homologies in an arctiid moth (Utetheisa ornatrix)

The nymphalid groundplan allows for the identification of homologous characters across species, making this archetype an invaluable tool for research on the development and evolutionary diversification of butterfly wing patterns. However, whether the groundplan applies to moths remains unknown. To better understand the domain of applicability of the nymphalid groundplan, we attempted to identify homologous elements in the dorsal forewing patterns of the hyper-variable arctiid moth Utetheisa ornatrix. Using trait correlation analyses, we located homologues such as the basal and central symmetry systems. However, we also identified two unique characters that are not found in modern renditions of the groundplan, which suggests that comparative research on arctiid wing patterns might require a return to earlier versions of the archetype that were not specifically tailored to research on butterflies. We also analysed the chemical basis underlying the conspicuous coloration of U. ornatrix, and found that non-melanic portions of the colour pattern are attributable to three pterin pigments: drosopterin, erythropterin and leucopterin. Given its pigmentary and morphological simplicity, the forewing pattern of this species could represent a primitive character state. If this is the case, developmental studies of U. ornatrix wing patterning could yield novel insights into pattern evolution in the Lepidoptera.

Duke Scholars

Author H. Frederik Nijhout Biology