Recent research on plant and insect impressions on Jomon-period pottery strongly suggests not only the presence of household pests such as the maize weevil (Sitophilus zeamais), but also the existence of storage facilities for acorns and nuts inside pit houses. The presence of insect pests provides indirect evidence for human-mediated crop propagation on a large scale. The evidence also suggests the possibility of introduction of maize weevils into north-eastern Japan by the Jomon people via the transportation of infested foodstuffs. However, this ‘diffusion by man’ hypothesis has remained unproven because it is possible that these insect pests and their preferred foods originated locally. Aiming to resolve this issue, we examined pottery vessels discovered at a Jomon site in Hokkaido that contain the remains of adult maize weevils. The geographical and temporal distribution of these vessels suggests a possibility of the human-mediated diffusion of maize weevils and chestnut cultivation across oceanic barriers by the Jomon people. Ultimately, we could not prove this hypothesis because of lack of entomological evidence, but we could prove that colonization of the cultivated plants had played a role in the spread of stored food pests. A lot of discoveries of the maize weevil by further impression survey will be expected as a clue to trace the relationship history between people, cultivated plant and pest insects.