Color Pattern on the Forewing of Micropterix (Lepidoptera: Micropterigidae): Insights into the Evolution of Wing Pattern and Wing Venation in Moths.

Sandra R Schachat,Richard L Brown

doi:10.1371/journal.pone.0139972

Sandra R Schachat, Richard L Brown

Open Access

https://doi.org/10.1371/journal.pone.0139972

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Abstract

Wing patterns are key taxonomic characters that have long been used in descriptions of Lepidoptera; however, wing pattern homologies are not understood among different moth lineages. Here, we examine the relationship between wing venation and wing pattern in the genus Micropterix, among the most basal extant Lepidoptera, in order to evaluate the two existing predictive models that have the potential to establish wing pattern element homologies for the order. The location of wing pattern elements along the costal margin of the wing in Micropterix is consistent with the predictions of the model proposed for Tortricidae by Brown and Powell in 1991, later modified by Baixeras in 2002. The predictive power of this model for such distantly related taxa suggests that the model may hold across various superfamilies within Lepidoptera, and supports the long-held notion that fasciae, not spots, are the most likely primitive wing pattern elements for the order. In addition, the location of wing pattern elements suggests that the wing vein commonly termed Sc1 may in fact be a different vein, which Comstock identified in Trichoptera and referred to as “a.”

Highlights

Many recent studies have examined the evolution of wing patterns in butterflies [1,2] and other macrolepidoptera [3,4,5,6]
The species M. aglaella, M. allionella, M. aureoviridella, M. rothenbachii, M. schaefferi 1, M. schaefferi 2, and M. tunbergella have wing patterns with six differentiated fasciae, all separated by visible interfascial areas (Fig 5)
A terminal fascia abuts or straddles Rs4 in Micropterix, but this fascia was not defined for Tortricidae in the "wing margin" model because this vein terminates on the outer margin, not the costa, of tortricid wings (Fig 1B)

Summary

Introduction

Many recent studies have examined the evolution of wing patterns in butterflies [1,2] and other macrolepidoptera [3,4,5,6]. The wing patterns of these taxa, and of other relatively derived moths such as Pyraloidea, are based on symmetry systems, which occur in different arrangements in various lineages [7] and consist of parallel lines in two or more colors overlaid on a light ground color [8,9,10,11]. Early-diverged moths, often small and brown, lack symmetry systems, and the evolutionary origin of their wing patterning is not known. Workers who study microlepidoptera have concluded that transverse bands, or fasciae, are primitive wing pattern elements for Lepidoptera and are constrained by venation [12,13,14], whereas workers who primarily study macrolepidoptera have concluded that spots, either “erratic” [7] or constrained by PLOS ONE | DOI:10.1371/journal.pone.0139972 October 5, 2015

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