Author:
Mugleston Joseph,Naegle Michael,Song Hojun,Bybee Seth M.,Ingley Spencer,Suvorov Anton,Whiting Michael F.
Abstract
Insects have developed incredible means to avoid detection by predators. At least five insect orders have species that resemble leaves. Katydids (Orthoptera : Tettigoniidae) are the most diverse and wide-ranging of the leaf-like insects. At least 14 of the 20 extant katydid subfamilies contain species with leaf-like wings. Although it is undisputed that many katydids resemble leaves, methods for delineating the leaf-like from non-leaf-like forms have varied by author and in many cases are not explicitly stated. We provide a simple ratio method that can be used to differentiate the leaf-like and non-leaf-like forms. Geometric morphometrics were used to validate the ratio method. Leaf-like wings have been independently derived in at least 15 katydid lineages. Relative rates of speciation were found to be greater in the non-leaf-like forms, suggesting that leaf-like wings within Tettigoniidae are not a driver of diversification. Likewise, throughout Tettigoniidae, selection seems to be favouring the transition away from leaf-like wings. However, within the large Phaneropterinae subclade, relative speciation and transition rates between the leaf-like and non-leaf-like forms do not differ significantly.
Subject
Ecology, Evolution, Behavior and Systematics