2023, Schuler, Hannes, Witkowski, Radosław, van de Vossenberg, Bart, Hoppe, Björn, Mittelbach, Moritz, Bukovinszki, Tibor, Schwembacher, Stefan, van de Meulengraaf, Bas, Lange, Uwe, Rode, Sabine, Andriolo, Alessandro, Bełka, Marta, Mazur, Andrzej, Battisti, Andrea

AbstractAmbrosia beetles of the Euwallacea fornicatus species complex are emerging tree pests with a broad host range including important agricultural crops. Native to Southeast Asia, these species were introduced into various countries, where they cause considerable damage to many tree species. Here we report several outbreaks of E. fornicatus s.l. in Europe. The first individuals were found in 2017 in a palm house of a botanical garden in Poznan (Poland) whereas in 2020 an outbreak was detected in a tropical greenhouse in Merano (Italy). In 2021, two additional outbreaks were detected in two greenhouses in Germany, in Erfurt and Berlin. For both cases in Germany it was possible to trace back the invasion to a distributor of exotic plants in the Netherlands where several infested plants were detected. Molecular analyses show that individuals from Poland and Italy are genetically identical but belong to a different mitochondrial clade than individuals in Germany which are identical to most individuals of two greenhouses in the Netherlands. Moreover, in the two greenhouses in the Netherlands we found beetles that belong to another haplotype of E. fornicatus and two haplotypes of E. perbrevis, a species in the E. fornicatus complex, which has not been previously intercepted in Europe. Our study provides novel insights into the invasion history of E. fornicatus and the eradication measures in Europe. Considering the potential of introduction and establishment of Euwallacea ambrosia beetles, particular attention should be paid to monitor the presence of these pests in tropical greenhouses across Europe.

2022, Witkowski, Radosław, Dyderski, Marcin K., Bełka, Marta, Mazur, Andrzej

Gnathotrichus materiarius (Fitch, 1858) is an alien ambrosia beetle from North America, that has been spreading across Europe since the 1930s. The species infests coniferous trees, excavating galleries in sapwood. However, to date very few studies have predicted changes in ambrosia beetle habitat suitability under changing climate conditions. To fill that gap in the current knowledge, we used the MaxEnt algorithm to estimate areas potentially suitable for this species in Europe, both under current climate conditions and those forecasted for the years 2050 and 2070. Our analyses showed areas where the species has not been reported, though the climatic conditions are suitable. Models for the forecasted conditions predicted an increase in suitable habitats. Due to the wide range of host trees, the species is likely to spread through the Balkans, the Black Sea and Caucasus region, Baltic countries, the Scandinavian Peninsula, and Ukraine. As a technical pest of coniferous sapwood, it can cause financial losses due to deterioration in quality of timber harvested in such regions. Our results will be helpful for the development of a climate-change-integrated management strategy to mitigate potential adverse effects.