This Vademecum is a practical guide developed for National Plant Protection Organizations, farmers, and professionals involved in the management of the Japanese beetle, Popillia japonica. It summarizes the results of the experiments carried out under the European project “Horizon 2020” called IPM-POPILLIA, which aimed to develop tools to eradicate or control this invasive beetle populations.Following a brief introduction on the invasive species's biology, ecology, and distribution, the document reviews surveillance and monitoring methodologies. It shows the development of a new AI-based trap, reports the guidelines for trap placement, and encourages the involvement of citizens for reporting the beetle and its spread through the mobile citizen science IPM app.In this document, the combined use of attract-and-kill methods with long-lasting insecticide-treated nets is suggested against the adults. This is complemented by the chemical spray of acetamiprid on the main host plants and the application of Kaolin clay as a repellent. For larval control, the soil application of autochthonous strains of the entomopathogenic nematode Heterorhabditis bacteriophora is proposed, along with other agronomic practices.Moreover, the guide includes a list of promising techniques that are either not yet available in Europe or still need to be developed for effective control. Finally, a timeline of scheduled interventions is also provided to assist with field application. The combined application of these strategies represents the most effective way to suppress or contain Popillia japonica.