We are proud to announce that the CFRI grew for one new doctor of science. Our colleague Dr. Ivan Lukić defended his doctoral dissertation at the Faculty of Forestry, University of Zagreb on November 9, 2018. Focus of his doctoral dissertation is the gypsy moth (Lymantria dispar L.), an insect that causes defoliation and is one of the most important forest pests in Croatia. This is the first research in Croatia that experimentally proved the amount of leaves (pedunculate oak and common beech) that one gypsy moth larvae consumes. The information is important because it helps in determination of critical number of gypsy moth egg masses, which in the end determines forest stands area for aerial treatment. Available data about the amount of leaves lacks the description about methodology and tree species used to gain this data. The results showed that instead of 12 g, gypsy moth larvae in average consumes about 3 g (dry weight) of leaves. The information in the end will help reduce the cost of aerial treatment in forest stands infested with this forest pest.