Do Ants Enhance Diversification in Lycaenid Butterflies? Phylogeographic Evidence From a Model Myrmecophile, Jalmenus Evagoras

Abstract

Abstract. The ant-tended Australian butterfly, Jalmenus evagoras, has been a model system for studying the ecology and evolution of mutualism. A phylogeographic analysis of mitochondrial DNA cytochrome oxidase I sequences from 242 butterflies (615 bp) and 66 attendant ants (585 bp) from 22 populations was carried out to explore the relationship between ant association and butterfly population structure. This analysis revealed 12 closely related butterfly haplotypes in three distinct clades roughly corresponding to three allopatric subpopulations of the butterflies. Minimal genetic diversity and widespread haplotypes within biogeographical regions suggest high levels of matrilineal gene flow. Attendant ants are significantly more diverse than was previously thought, with at least seven well-defined clades corresponding to independent morphological determinations, distributed throughout the range of the butterflies. Nested analysis of molecular variance showed that biogeography, host plant, and ant associate all contribute significantly in explaining variation in butterfly genetic diversity, but these variables are not independent of one another. Major influences appear to come from fragmentation due to large-scale biogeographical barriers, and diversification following a shift in habitat preference. A consequence of such a shift could be codiversification of the butterfly with habitatadapted ants, resulting in apparent phylogenetic concordance between butterflies and ants. The implications of these results are discussed in terms of possible effects of ant attendance on the diversification of Lycaenidae as a whole.

Congruence and Diversity of Butterfly-Host Plant Associations at Higher Taxonomic Levels

“…This in turn could explain the higher host plant diversity for Theclinae that was found in this study and previous studies [14], [74]–[76], and may also explain the species diversity in other subfamilies in the Lycaenidae and Riodinidae [77]. Recently, Megens et al [78] suggested that the timing of a basal radiation in Arhopala (the most speciose genus of Theclinae, with 9% of the species in Southeast Asia) coincided with major climate changes commencing during the middle Miocene.…”

Does the DNA barcoding gap exist? – a case study in blue butterflies (Lepidoptera: Lycaenidae)

“…These sequences were supplemented by 385 further sequences of Lycaenidae deposited in GenBank as of March, 2006 (Table 5). They include sequences from further studies on Agrodiaetus [29,44], the Palaearctic genus Maculinea [54], Nearctic Lycaeides melissa [55], the Oriental genus Arhopala [46,50], the Australian genera Acrodipsas [56] and Jalmenus [57], and the South African Chrysoritis [58] as well as a few sequences which have only been used as outgroups in non-Lycaenidae studies (e.g. [59,60]).…”

Ant association facilitates the evolution of diet breadth in a lycaenid butterfly

“…By contrast, the role of mutualistic interactions in evolutionary diversification has been less explored [5,6]. Butterflies in the families Lycaenidae and Riodinidae have been a focal point for interest in the connection between diversification and mutualistic interaction [7][8][9][10]. Approximately, one third of all butterfly species are lycaenids, and more than half of all lycaenids are myrmecophilous: they engage in interactions with ants that are either mutualistic, commensalistic or parasitic [11].…”