To determine the susceptibility of important species of eucalypt trees in Chile to Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), an insect that was detected on Eucafyptus camaldulensis Dehn. in 2002 in Santiago, which causes defoliation of trees affected, and even their death in severe infestations, a field evaluation of an induced infestation was performed in 2004 of one-year-old plants of E. camaldulensis, E. nitens Deane & Maiden, and E. globulus Labill Growths of infested plants were compared with uninfested controls, using destructive sampling at 15, 30, 45, and 60 days. Also, observations were made regarding the duration of the development stages of the insect during two generations. The only species that was susceptible to the psyllid was E. camaldulensis, while it did not develop on E. nitens and E. globulus. The plants of E. camaldulensis infested with adults of G. brimblecombei had small and not significant reductions in plant height, diameter at trunk base, and foliar area, in comparison with control plants after two months. In the Santiago bioclimatic zone, this insect completed the first generation in 30 days (February-March), and the second in 36 days (March-April).