TRICHODERMA-INDUCED SYSTEMIC RESISTANCE AGAINST THE SCALE INSECT (UNASPIS MABILIS LIT & BARBECHO) IN LANZONES (LANSIUM DOMESTICUM CORR.) SUMMARY Unaspis mabilis infestations have been causing huge economic losses to the lanzones industry in the Philippines since 2009. This study, therefore, seeks to determine the use of Trichoderma as myco-biocontrol agent to increase lanzones (Lansium domesticum) defense and resistance against this insect. Two experiments were designed to test for the protective and rescuing capacity of Trichoderma inoculation against the insect pest. For both experiments, leaf area, leaf count, scale insect populations and densities were observed over time. Additionally, to assess the phytochemical response of the plants, the concentrations of jasmonic acid, salicylic acid, total phenol content, and total flavonoid content were also measured in the rescuing capacity experiment. Results indicated that the plants inoculated with Trichoderma were performing better, showing lower populations and slower growth rate of the insect, than the uninoculated plants for both the protective and rescuing capacity experiments. Phytochemical analysis revealed the presence of tannins, phlobatannins, flavonoids, steroids, glycosides, and alkaloids in the leaves of L. domesticum. Total phenols and flavonoids showed decreasing concentrations as the infestation progressed, while the concentrations of jasmonic acid and salicylic acid in scaleinsect-infested plants were found to be influenced by the inoculation of the plants with Trichoderma.