The potential introductions and subsequent establishment of invasive alien species are increasing with expanding world trade. Of alien insects designated as “Invasive Alien Species”, only two species have been established in Japan: the Argentine ant Linepithema humile and the European bumblebee Bombus terrestris. Despite of the eradication attempts, their invasions still continue and are causing the ecological and economic damages. The difficulty of the eradication is associated with the ecological characteristics: L. humile is highly polygynous and possesses a social structure, called unicoloniality, whereby individuals mix freely among separated nests. Furthermore, the species builds frequently-changed nest and easily move its colony to new location. Therefore, saturation raid should be conducted throughout the infested area. Here, we demonstrate the eradication project of L. humile in Tokyo to provide successful example for the support the ongoing battle against L. humile. Bombus terrestris is also highly productive, and developing new measures of eradication, beside ineffective capture using insect nets, is required. Hence, we first conduct toxicity test on bumblebees both in the laboratory and in the field. It is the world first trial to control bees used as a valuable pollinator.