Periodic Reporting for period 3 - IPM-Popillia (Integrated Pest Management of the invasive Japanese Beetle, Popillia japonica)
Reporting period: 2023-09-01 to 2024-12-31
The recent invasion of the Japanese beetle, Popillia japonica, into continental Europe threatens the entire agricultural sector, as well as the biodiversity in the invaded area. A thorough review in the course of the project revealed that there are more than 400 host plants of Japanese beetles known worldwide. These include many important crops, like wine, fruit trees, soft berries, maize and soybean. IPM-Popillia aimed at confining the spread of the new pest, and preventing the build-up of high population densities that cause economic loss to agricultural crops and increase migration pressure of the Japanese beetles. The objectives of the project IPM-Popillia were grouped in four overarching aims:
1. Identifying the Japanese beetles’ pathways of entry and spread.
This included the development of fast and reliable monitoring tools, risk estimation for the invasion on regional level, and the provision of an optimal surveillance strategy for Europe. Objectives also comprised support to EU policy in the management of high priority pests in general, and raising public awareness for invasive pest species via citizen science tools.
2. Understanding the drivers of Japanese beetles’ population development
This included our efforts to characterize abiotic factors and identify the most relevant groups of organisms associated with P. japonica in infested and non-infested areas of the same region, and to understand the underlying processes that lead to pest establishment or failure of establishment.
3. Providing an IPM Toolbox for Japanese beetle control
The objectives of this work package were to develop a range of sustainable control options of larvae and of adults of the Japanese beetle, with a focus on biocontrol and on IPM. A set of tools appropriate to control the invasive pest on sites with low and high pest abundance, respectively, was the outcome of this work package.
4. Developing sustainable Japanese Beetle management in Europe
The economic and socioeconomic impacts of the P. japonica invasion, and the feasibility of implementing the control measures developed in the frame of the project, were investigated. Moreover, a main deliverable of the project was produced, an easy to comprehend and concise guideline for all stakeholders involved into sustainable Japanese beetle management in Europe.
1. Identifying the Japanese beetles’ pathways of entry and spread.
This included the development of fast and reliable monitoring tools, risk estimation for the invasion on regional level, and the provision of an optimal surveillance strategy for Europe. Objectives also comprised support to EU policy in the management of high priority pests in general, and raising public awareness for invasive pest species via citizen science tools.
2. Understanding the drivers of Japanese beetles’ population development
This included our efforts to characterize abiotic factors and identify the most relevant groups of organisms associated with P. japonica in infested and non-infested areas of the same region, and to understand the underlying processes that lead to pest establishment or failure of establishment.
3. Providing an IPM Toolbox for Japanese beetle control
The objectives of this work package were to develop a range of sustainable control options of larvae and of adults of the Japanese beetle, with a focus on biocontrol and on IPM. A set of tools appropriate to control the invasive pest on sites with low and high pest abundance, respectively, was the outcome of this work package.
4. Developing sustainable Japanese Beetle management in Europe
The economic and socioeconomic impacts of the P. japonica invasion, and the feasibility of implementing the control measures developed in the frame of the project, were investigated. Moreover, a main deliverable of the project was produced, an easy to comprehend and concise guideline for all stakeholders involved into sustainable Japanese beetle management in Europe.
Within WP1,
• An innovative, remotely controlled monitoring trap prototype was designed, and tested at several locations and different European countries. The trap reached marketability at the end of the project and is available on the market in the first half of 2025.
• The IPM-Popilla Citizen Science App was released and enables immediate upload of beetle sightings; recently, the App has been opened for co-use with another project and is now also used for monitoring of two invasive fruit flies.
• P. japonica habitat suitability predictors have been combined with an estimate of “connectivity” of the European regions (train routes, plane routes, road cargo routes) and other relevant data into a risk based surveillance model.
• The worldwide colonization route of P. japonica has been reconstructed. Investigations have shown that P. japonica has been introduced from the US to Europe at least twice.
Within WP2,
• a fairly complete and annotated genome of P. japonica genome has been produced in the course of the project.
• Sites with heavy and with low population densities of P. japonica within the same region have been investigated, and the influence of abiotic parameters as well as the soil microbiome and selected arthropods have been investigated.
New candidate biocontrol agents have been identified, e.g. the entomopathogenic fungus Beauveria pseudobassiana, which seems to be better adapted to above ground environmental conditions. The latter may come in handy for biocontrol of adult beetles in crop canopies.
Within WP3,
• Strains of entomopathogenic nematodes as natural antagonists of P. japonica larvae have been isolated and tested, and have reached efficacy levels of up to 90%.
• Attract-and-kill devices with LLINs (long-lasting insecticide-treated nets) have been tested successfully and are already used in practice for the containment of outbreak populations with low to medium population densities.
• Horizontal transmission of fungal spores between infested and healthy P. japonica adults has been proved in the lab, and in two independent field experiments. Autodissemination may be a promising tool in P. japonica control.
Within WP4,
• A project website was designed and launched in the internet. Furthermore, social media activities were started, and web content has been created for extended outreach to users.
• A survey on the economic losses of the P. japonica invasion, and the willingness to pay for biological control of the invasive pest has been carried out.
• The main deliverable of the project, our so-called IPM-Popillia Vade mecum, has been released. It is designed to be easily comprehensible, represents a good mixture between being concise and exhaustive, and covers all major aspects of P. japonica management.
• An innovative, remotely controlled monitoring trap prototype was designed, and tested at several locations and different European countries. The trap reached marketability at the end of the project and is available on the market in the first half of 2025.
• The IPM-Popilla Citizen Science App was released and enables immediate upload of beetle sightings; recently, the App has been opened for co-use with another project and is now also used for monitoring of two invasive fruit flies.
• P. japonica habitat suitability predictors have been combined with an estimate of “connectivity” of the European regions (train routes, plane routes, road cargo routes) and other relevant data into a risk based surveillance model.
• The worldwide colonization route of P. japonica has been reconstructed. Investigations have shown that P. japonica has been introduced from the US to Europe at least twice.
Within WP2,
• a fairly complete and annotated genome of P. japonica genome has been produced in the course of the project.
• Sites with heavy and with low population densities of P. japonica within the same region have been investigated, and the influence of abiotic parameters as well as the soil microbiome and selected arthropods have been investigated.
New candidate biocontrol agents have been identified, e.g. the entomopathogenic fungus Beauveria pseudobassiana, which seems to be better adapted to above ground environmental conditions. The latter may come in handy for biocontrol of adult beetles in crop canopies.
Within WP3,
• Strains of entomopathogenic nematodes as natural antagonists of P. japonica larvae have been isolated and tested, and have reached efficacy levels of up to 90%.
• Attract-and-kill devices with LLINs (long-lasting insecticide-treated nets) have been tested successfully and are already used in practice for the containment of outbreak populations with low to medium population densities.
• Horizontal transmission of fungal spores between infested and healthy P. japonica adults has been proved in the lab, and in two independent field experiments. Autodissemination may be a promising tool in P. japonica control.
Within WP4,
• A project website was designed and launched in the internet. Furthermore, social media activities were started, and web content has been created for extended outreach to users.
• A survey on the economic losses of the P. japonica invasion, and the willingness to pay for biological control of the invasive pest has been carried out.
• The main deliverable of the project, our so-called IPM-Popillia Vade mecum, has been released. It is designed to be easily comprehensible, represents a good mixture between being concise and exhaustive, and covers all major aspects of P. japonica management.
The most important advance beyond the state-of-the-art is that our IPM-Toolbox for the control of P. japonica relies exclusively on environmentally friendly control measures. These are either biocontrol methods or IPM approaches with low environmental impact. If pesticide input is unavoidable (e.g. in vineyards of highly infested areas), we show ways of how to reduce pesticide input by combining the latter with biological or biotechnical measures.
IPM-Popillia provided the necessary innovations to enhance reliability and responsiveness of monitoring. As an example, risk mapping developed in the frame of the project predicted the region of Zurich as highly susceptible for a Japanese beetle outbreak, and the first population of P. japonica found north of the alps has definitely been found in Zurich.
IPM-Popillia produced results which can immediately be set in place for control of the invasive pest. E.g. our attract-and-kill strategy by combining the P. japonica specific lure with long-lasting insecticide-treated nets has proiven to be efficient with minimum work load and at an affordable price. It is currently already used in Italian and in Swiss outbreak regions for the control of adults. Another method, the autodissemination concept using entomopathogenic fungi, has not reached marketability during the project, but has been confirmed to be efficient in two independent field experiments. This approach will be investigated further in follow-up projects and we hope that it may be available on the market after another two or three field test seasons.
IPM Popillia was not able to find a low risk substance which can completely substitute the use of synthetic pesticides. However, our experiments give evidence that the use of low risk substances, such as Kaolin clay, enables to reduce substantially the need for pesticide spray against P. japonica, even under high pest pressure conditions. The same measure may even be sufficient to replace pesticide input completely in low and medium pest pressure situations.
IPM-Popillia provided the necessary innovations to enhance reliability and responsiveness of monitoring. As an example, risk mapping developed in the frame of the project predicted the region of Zurich as highly susceptible for a Japanese beetle outbreak, and the first population of P. japonica found north of the alps has definitely been found in Zurich.
IPM-Popillia produced results which can immediately be set in place for control of the invasive pest. E.g. our attract-and-kill strategy by combining the P. japonica specific lure with long-lasting insecticide-treated nets has proiven to be efficient with minimum work load and at an affordable price. It is currently already used in Italian and in Swiss outbreak regions for the control of adults. Another method, the autodissemination concept using entomopathogenic fungi, has not reached marketability during the project, but has been confirmed to be efficient in two independent field experiments. This approach will be investigated further in follow-up projects and we hope that it may be available on the market after another two or three field test seasons.
IPM Popillia was not able to find a low risk substance which can completely substitute the use of synthetic pesticides. However, our experiments give evidence that the use of low risk substances, such as Kaolin clay, enables to reduce substantially the need for pesticide spray against P. japonica, even under high pest pressure conditions. The same measure may even be sufficient to replace pesticide input completely in low and medium pest pressure situations.