The genomic history and global migration of a windborne pest

Many insect pests, including the brown planthopper (BPH), undergo windborne migration that is challenging to
observe and track. It remains controversial about their migration patterns and largely unknown regarding the
underlying genetic basis. By analyzing 360 whole genomes from around the globe, we clarify the genetic sources
of worldwide BPHs and illuminate a landscape of BPH migration showing that East Asian populations perform
closed-circuit journeys between Indochina and the Far East, while populations of Malay Archipelago and South
Asia undergo one-way migration to Indochina. We further find round-trip migration accelerates population dif-
ferentiation, with highly diverged regions enriching in a gene desert chromosome that is simultaneously the spe-
ciation hotspot between BPH and related species. This study not only shows the power of applying genomic
approaches to demystify the migration in windborne migrants but also enhances our understanding of how sea-
sonal movements affect speciation and evolution in insects.