A new chapter of the Japanese beetle invasion saga: predicting suitability from long-infested areas to inform surveillance strategies in Europe

Abstract

The Japanese beetle (Popillia japonica) is a polyphagous pest that spreads rapidly and is estimated to cost more than 460 M$/year in damage and control in the USA alone. This study provides risk maps to inform surveillance strategies in Continental Europe, following the beetle′s introduction and successive spread in the last decade. We developed a species distribution model using a machine-learning algorithm, considering factors relevant to the beetle′s biology, climate, land use and human-related variables. This analysis was performed using presence-only data from native and invaded ranges (Japan, North America, Azores archipelago - Portugal). We gathered more than 30 000 presence data from citizen science platforms and standardized surveys, and generated pseudo-absences using the target-group method. We used the environmental structure of data to randomly sample pseudo-absences, and evaluate model performance via a block cross-validation strategy. Our results show that climate, in particular seasonal trends, and human-related variables, are major drivers of the Japanese beetle distribution at the global scale. Risk maps show that Central Europe can be considered as suitable, whereas Southern and Northern European countries are at lower risk. The region currently occupied is among the most suitable according to our predictions, and represents less than 1% of the highest suitable area in Europe. A major cluster of high suitability areas is located near the currently infested zone, whereas others are scattered across the continent. This highlights the importance of designing surveillance strategies considering both active insect dispersal and the possibility of hitchhiking to reach distant areas.

Private management costs of Popillia japonica: a study of viticulture in Italy

“…In addition, the average application rate for products with acetamiprid was higher for affected plots. This increase in application for insecticides containing acetamiprid and deltamethryn makes sense since they are among the active substances registered against adults of the Japanese beetle ( 3 ).…”

“…The beetle Popillia japonica (Japanese beetle), native to Japan, is an invasive insect pest in Europe and considered a major threat to European agriculture. It can feed on more than 300 different host plants ( 1 ) and there are many areas in Europe with suitable climatic conditions for its proliferation ( 2 , 3 ). The beetle is considered a priority pest candidate in the EU ( 4 ) and ranked as the 2 nd most dangerous pest for crops by the European Food and Safety Authority ( 5 ).…”

A new chapter of the Japanese beetle invasion saga: predicting suitability from long-invaded areas to inform surveillance strategies in Europe

“…This results in 6844 presence cells and 49010 pseudo-absence cells. The entire dataset, including presence/pseudoabsence data and environmental variables, is available in raster format at a 4km x 4km resolution (Borner et al, 2022).…”

A nationwide pest risk analysis in the context of the ongoing Japanese beetle invasion in Continental Europe: The case of metropolitan France

“…Four factors that can affect the establishment of P. japonica in a new territory have been identified: (1) mild temperature, (2) sufficient humidity for survival and development, (3) presence of host plants and (4) lack of natural enemies. The likelihood of outdoor establishment is considered high, based on the findings from species distribution models ( 23 – 26 ), the high diversity and abundance of host plants in metropolitan France ( Figure 2 ), and the limited impact of natural enemies. The uncertainty is considered low.…”