Adaptation to different environments can promote speciation and increase diversity. This simple and classic idea has now been matured and well-organized as the concept of ‘ecological speciation’. More recently, innovative molecular techniques such as next-generation sequencing system and microanalytical techniques such as gas chromatography-mass spectrometry (GC-MS) analysis are enabling us to elucidate both the proximate and ultimate mechanisms of adaptation and speciation even in non-model organisms. Phytophagous insects could be especially suitable to addressing these issues because of the tight association between divergent adaptation to different host plants and reproductive isolation. In the symposium, we will introduce the latest challenges to investigating the genomic and chemical background of ecological speciation, focusing on host plant adaptation in different systems of phytophagous insects. Work on the genomic and chemical basis of speciation in insects is accumulating, but is still in its infancy. Thus, now is an ideal time to introduce current understanding of the field to Japanese researchers studying ecology, genetics, chemical ecology, and evolution.

*Commentator: Masakado Kawata (Tohoku University)