Using X-ray tomography to investigate species-specific colonization patterns of ambrosia beetles in flooded trees

This study employs X-ray tomography to explore species-specific colonization patterns of ambrosia beetles in flooded trees. The research focuses on elucidating the impact of tree species on host selection and colonization success among ambrosia beetles under simulated flooding conditions. The investigation compares the variations in the number of entry holes (a proxy for host selection) and the number of successful galleries (a proxy for colonization success) across eight distinct tree species prevalent in orchard and forest ecosystems. The species investigated include Malus sylvestris, Prunus armeniaca, Prunus avium, Pyrus pyraster, Corylus avellana, Carpinus betulus, Quercus ilex, and Quercus robur. The results highlight the indispensable role of ethanol in the plant-host relationship, influencing both host selection mechanisms and colonization success of four species of ambrosia beetles: Xylosandrus crassiusculus, Xylosandrus germanus, Xyleborinus saxesenii and Anisandrus dispar. The study reveals differential effects of flooding stress on these ambrosia beetle species boring activities and colonization success, with trees in the Rosales group being subjected to higher attack frequencies and higher colonization success levels than those in the Fagales group. Furthermore, the research emphasizes the potential threat of ambrosia beetles in orchards and nurseries, in particularly Xylosandrus crassiusculus was proven to be highly adaptable to different conditions and tree species, thus posing a potential threat for trees that are undergoing flooding stress. As climate change increases the frequency of flooding events worldwide, understanding ambrosia beetle behaviour becomes crucial for effective monitoring and pest management in both managed and natural environments.