Executive Summary: A wide range of insect herbivores infest Eucalyptus trees in New Zealand, particularly insects native to Australia. The most damaging defoliators are the paropsine beetles. Paropsis charybdis and Paropsisterna cloelia (EVB). In 2019, EVB was present in the North Island, however in the summer of 2019/2020 EVB spread to the upper South Island and now causes considerable defoliation to Eucalyptus. Few studies have examined Eucalyptus tolerance and resistance to insect defoliation. Understanding paropsine feeding preferences and their impacts is important to inform the selection of New Zealand Dryland Forest Initiative (NZDFI) breeding lines to establish a healthy, productive and durable Eucalyptus timber industry in New Zealand. This research aims to determine how paropsine insects interact with plantation eucalypts in New Zealand. This was achieved by quantifying the resistance and/or tolerance of Eucalyptus species/families/genotypes to paropsine attack. Paropsine defoliation across seven different Eucalyptus species (variation at species level), E. bosistoana and E. tricarpa families (variation at family level), and E. bosistoana clones of different genotypes (variation at genotype level) were quantified. For each tree sampled, the number and length of the new growth shoots, height increment, DBH increment, and defoliation using the CDI (Crown Damage Index) were assessed to quantify defoliation and resistance/tolerance on two or three occasions between 2019-2021. CDI was used to measure resistance, whereas growth measurements (DBH, height and new shoot growth) were used to assess tolerance to propsine browse.