A global phylogeny of leafmining Ectoedemia moths (Lepidoptera: Nepticulidae): exploring host plant family shifts and allopatry as drivers of speciation.

Camiel Doorenweerd,Erik J Van Nieukerken,Steph B J Menken,William J Etges

doi:10.1371/journal.pone.0119586

Camiel Doorenweerd, Erik J Van Nieukerken + Show 2 more

Open Access

https://doi.org/10.1371/journal.pone.0119586

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Journal: PloS one	Publication Date: Mar 18, 2015
Citations: 81	License type: CC BY 4.0

Affiliation: Naturalis Biodiversity Center, University of Amsterdam

Abstract

BackgroundHost association patterns in Ectoedemia (Lepidoptera: Nepticulidae) are also encountered in other insect groups with intimate plant relationships, including a high degree of monophagy, a preference for ecologically dominant plant families (e.g. Fagaceae, Rosaceae, Salicaceae, and Betulaceae) and a tendency for related insect species to feed on related host plant species. The evolutionary processes underlying these patterns are only partly understood, we therefore assessed the role of allopatry and host plant family shifts in speciation within Ectoedemia.MethodologySix nuclear and mitochondrial DNA markers with a total aligned length of 3692 base pairs were used to infer phylogenetic relationships among 92 species belonging to the subgenus Ectoedemia of the genus Ectoedemia, representing a thorough taxon sampling with a global coverage. The results support monophyletic species groups that are congruent with published findings based on morphology. We used the obtained phylogeny to explore host plant family association and geographical distribution to investigate if host shifts and allopatry have been instrumental in the speciation of these leafmining insects.SignificanceWe found that, even though most species within species groups commonly feed on plants from one family, shifts to a distantly related host family have occasionally occurred throughout the phylogeny and such shifts are most commonly observed towards Betulaceae. The largest radiations have occurred within species groups that feed on Fagaceae, Rosaceae, and Salicaceae. Most species are restricted to one of the seven global biogeographic regions, but within species groups representatives are commonly found in different biogeographic regions. Although we find general patterns with regard to host use and biogeography, there are differences between clades that suggest that different drivers of speciation, and perhaps drivers that we did not examine, have shaped diversity patterns in different clades.

Highlights

Insect herbivores constitute the most species-rich group of insects and more than half of the world’s known species are insects [1]
As phylogenetic studies of insects as well as plants are becoming more complete in terms of taxon sampling, more robust by including more genetic markers and better dated with molecular clock methods, a complete picture of species interaction patterns as well as a more complete understanding of the relative importance of the various evolutionary factors that drive herbivorous insect radiations is coming within reach [5,6,7]
The resulting new classification with all described and undescribed, but included in the phylogeny, Ectoedemia species is provided in S5 Table and is outlined as following: Genus Ectoedemia Busck, 1907 Subgenus Zimmermannia Hering, 1940 Subgenus Ectoedemia s. s

Summary

Introduction

Insect herbivores constitute the most species-rich group of insects and more than half of the world’s known species are insects [1]. During ecological speciation new species arise after diverging in resource use, which for herbivores is commonly a dietary change, and this may happen in sympatry or allopatry [18,19,20]. It has been argued quite a few times in the past century, that ecological factors driving speciation are often overestimated, whereas geographic factors are underestimated [16,21,22]. Host association patterns in Ectoedemia (Lepidoptera: Nepticulidae) are encountered in other insect groups with intimate plant relationships, including a high degree of monophagy, a preference for ecologically dominant plant families (e.g. Fagaceae, Rosaceae, Salicaceae, and Betulaceae) and a tendency for related insect species to feed on related host plant species. The evolutionary processes underlying these patterns are only partly understood, we assessed the role of allopatry and host plant family shifts in speciation within Ectoedemia

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