In a trial established to produce biomass for bioenergy from Eucalyptus camaldulensis Dehnh, ring-debarking in branches and stems caused by Ectinogonia buquetti Spin. (Coleoptera: Buprestidae) was detected. Larvae of this native insect were recently detected in Eucalyptus sp. wood in central Chile (Valparaiso Region). This is the first document describing the damage caused by the adult insect on the bark of Eucalyptus camaldulensis seedlings. This report presents the methodology developed to evaluate damage and describes the frequency and intensity of the damage based on the lost leaf area. In some experimental units, more than 65 % of trees presented damage, where the average leaf area lost per tree was higher than 28 %. Moreover, a direct relation between the average damage per tree level and the attack frequency per experimental unit was detected, and both were inversely related to plantation density. The drop in the photosynthetic surface area will affect biomass yield in a magnitude that may only be estimated through successive measurements.