Deep phylogeographical structure and parallel host range evolution in the leaf beetle Agelasa nigriceps

Abstract

To understand the mechanisms behind the diversification of herbivorous insects through insect-plant interactions, it is important to know how the insects change their diet breadth in response to environmental changes. In this study, we investigated the phylogeographical pattern of the leaf beetle Agelasa nigriceps to infer the evolutionary history of its host range. While this beetle commonly uses Actinidia arguta (Actinidiaceae) as a host plant, it has been recorded recently on Pterostyrax hispidus (Styracaceae), which is now increasing in abundance at some localities in Japan due to the indirect effects of high population size of a mammalian herbivore. Considerable variation among populations in the ability of Ag. nigriceps to use P. hispidus suggests that P. hispidus is a newly acquired host plant for this beetle. Phylogenetic analyses using mitochondrial DNA sequences and amplified fragment length polymorphism (AFLP) revealed a high degree of phylogeographical structure in Ag. nigriceps throughout Japan, which is consistent with the hypothesis that several glacial refugia existed in the Japanese archipelago. In contrast, no genetic structure associated with the host plants was detected. Both the mitochondrial DNA and AFLP analyses showed that populations that can use P. hispidus are polyphyletic. These results and geographical variation in host use suggest that the host range expansion to a novel host, P. hispidus, is a very recent and possibly ongoing phenomenon and has occurred independently in several regions. Our study illustrates that the host range of herbivorous insects can evolve repeatedly in response to similar environmental changes.

Genetics of lineage diversification and the evolution of host usage in the economically important wheat curl mite, Aceria tosichella Keifer, 1969

“…Furthermore, our results shed new light on the mechanisms associated with specialization and generalization, each appearing to have evolved convergently in unrelated WCM lineages on numerous occasions. Such a pattern supports the notion that host use strategy can be highly dynamic in herbivores [ 11 , 105 ], although host specificity is also known to be phylogenetically constrained in phytophagous insects [ 106 ] and in animal parasites [ 107 ]. The demographic histories of generalist mite lineages also appear to be dynamic, with evidence suggesting that many have undergone major demographic expansion events, with ongoing gene flow among populations from different hosts.…”

Intense Browsing by Sika Deer (Cervus Nippon) Drives the Genectic Differentiation of Hairy Nettle (Urtica Thunbergiana) Populations

“…We performed AFLP analysis following the methods described in Kohyama et al (2014). In brief, we conducted the restriction, adapter ligation, pre-selective and selective ampli cation using the AFLP Plant Mapping Kit (Applied Biosystems, Foster City, CA, USA).…”

Phylogeographic patterns of Lygus pratensis (Hemiptera: Miridae): Evidence for weak genetic structure and recent expansion in northwest China

“…Molecular phylogeographic results have been used to reconstruct the evolutionary history of species by revealing colonization history, range expansion, and spatial and temporal genetic variation [2, 3]. The phylogeographic patterns of many organisms, whose evolution was affected by vicariance [4–6], climatic changes [7], hosts [8] and human interference events [9–11] have been studied using molecular data.…”