Giselher Grabenweger ^1* Giulia Torrini ² William D Hutchison ³

• ¹ Research Group Extension Arable Crops, Agroscope, Zürich, Switzerland
• ² CREA - Research Center for Plant Protection and Certification, Florence, Italy
• ³ Department of Entomology, University of Minnesota, St. Paul, United States

The arrival of the Japanese Beetle, Popillia japonica Newman, in continental Europe (Pavesi 2014) has sparked new interest in this well-known invasive species, and initiated international collaboration for its control, not only within Europe but also across the Atlantic. A session dedicated to this invasive pest at the International Congress of Entomology in Helsinki in 2022 enabled exchange between leading Popillia experts from the US and Canada and scientists involved in the containment of the Japanese Beetle in Europe. The most important work presented during this session is compiled in the presented e-book, along with other research updates regarding the biology, ecology and management of P. japonica, which was not included in previous reviews about this pest (Potter and Held, 2002, Shanovich et al., 2019, Altohoff & Rice 2022).In this collection, entitled "Focus on Popillia japonica," two articles deal with more robust estimates of P. japonica damage to important crops like wine grapes. Ebbenga et al. (2022) estimates the impact of P. japonica infestation on yield and grape quality. Although it is long known that grapes (cultivated and wild) is one of the beetle's preferred host plants, this paper is the first to assess the damage and impact on several berry/juice quality parameters. (2022) performed a pest risk analysis for the pest-free (to date) region of Metropolitan France, which is quite close to infested regions geographically and also well-connected with infested zones by major routes of transport of humans and goods. They recommend early detection and early-stage eradication measures against P. japonica in outbreak zones as the most important measure to control the risk of pest invasion.The development of environmentally friendly control measures against the invasive pest is the main goal of the last two contributions to this e-book. Graf et al. (2023) present experiments for biological control of P. japonica with entomopathogenic fungi (EPF). Their study gives evidence that Japanese beetle larvae are resistant to EPF infection, while adults are very susceptible. Consequently, more resources should be invested into the control of adult P. japonica with EPF. Carroll et al. (2023) tested gene silencing by feeding P. japonica with double-stranded RNA as a novel control approach. They show that fast degradation of dsRNA in the insect's gut may be avoided by micro-encapsulation, which increases gene knock-down and, consequently, efficacy of the control approach against the invasive pest.As you read this summary, P. japonica continues to expand its range, slowly but steadily, in the US and Canada as well as in Italy and Switzerland, bringing new challenges to producers as well as plant health specialists on both continents. It is clear that single control measures will never stop this invasion, and that elaborate IPM strategies are necessary for successful P. japonica containment. We are hopeful that the contributions compiled in this e-book will contribute to the development of a sustainable response to the ongoing invasion.