Cryptic matters: overlooked species generate most butterfly beta-diversity

to reproductively interfere between them (Pigot and Tobias 2013). Results for a series of cryptic butterfly species revealed only restricted contact zones on mainland and chequered distributions over narrow (3–10 km) sea straits (Dincă et al. 2011, Dapporto et al. 2012, Sañudo-Restrepo et al. 2013). If chequered distributions are overrepresented among cryptic species, they could encompass a disproportionally high fraction of beta-diversity turnover, a direct measure of the frequency of species replacement from site to site. Spatial turnover is recognized as a fundamental parameter in ecology and is increasingly used to detect biogeographic patterns (Holt et al. 2013). To assess the effects of ignoring cryptic diversity, we studied the biogeographical properties of cryptic species uncovered since 1970, after the cornerstone work of Higgins and Riley (1970) that have been generally accepted by the scientific community. In particular, we explored the prevalence of chequered distribution patterns among groups of cryptic taxa in west Mediterranean butterflies, which represent one of the best-studied invertebrate groups, especially regarding their taxonomy and distribution. We also assessed if cryptic taxa account for an unbalanced fraction of the beta-diversity Ecography 37: 001–005, 2014 doi: 10.1111/ecog.00762 © 2014 The Authors. Ecography © 2014 Nordic Society Oikos Subject Editor: Jeremy T. Kerr. Editor-in-Chief: Carsten Rahbek. Accepted 10 September 2014