Effect of Coraebus florentinus (Coleoptera: Buprestidae) on the Bending Strength of Holm Oak (Quercus ilex) Branches

The holm oak (Quercus ilex) is a keystone species in Mediterranean ecosystems due to its ecological relevance and economic value. However, its forests are experiencing increasing decline driven by poor regeneration, prolonged drought, diseases, and wood-boring insect infestations. This study evaluates the impact of Coraebus florentinus on the mechanical properties of holm oak wood. Laboratory bending tests on healthy and insect-damaged branches assessed resistance in relation to applied load, diameter, and length until maximum deflection and breakage. Results showed that C. florentinus damage (considered as a categorical variable, it was not quantified based on the presence or absence of visible symptoms and characteristic larval galleries, and we acknowledge this as a limitation of the study) altered the bending behavior of holm oak branches, mainly by reducing deformation capacity before failure. However, bending strength showed a site-dependent response, indicating that the mechanical effect of infestation may vary according to local branch characteristics and damage distribution. Infestations of C. florentinus in Q. ilex stands, whether used for timber production or pasture systems, may contribute to the loss of photosynthetically active branches and potentially affect tree productivity.