Abstract The red gum lerp psyllid, Glycaspis brimblecombei Moore, 1964 (Hemiptera: Aphalaridae), an insect pest originating in Australia and which feeds only on Eucalyptus L'Hér. (Myrtales: Myrtaceae) plants, has spread to several countries. The populations of this insect commonly reach high populations on Eucalyptus plants since its entry into Brazil, and also indicated an unrecorded behavioral. The objectives of this study were to describe a peculiar adaptation in the feeding habit of G. brimblecombei and to register the new habit. The oviposition and feeding by G. brimblecombei, commonly, on the leaves of Eucalyptus, started to occur, also, on lignified twigs. This suggests a not yet recorded adaptation of this insect to reduce insect × plant intraspecific competition.