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Heteroperreyia hubrichi Malaise (Hymenoptera: Pergidae), a foliage feeding sawfly of Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae), was studied to assess its suitability as a classical biological control agent of this invasive weed in Hawaii. No-choice host-specificity tests were conducted in Hawaiian quarantine on 20 plant species in 10 families. Besides the target weed, adult females oviposited on four test species. Females accepted the Hawaiian native Rhus sandwicensis A. Gray (Sapindales: Anacardiaceae) as an oviposition host equally as well as the target species. The other three species received significantly fewer eggs. Neonate larvae transferred onto test plants successfully developed to pupae on S. terebinthifolius (70% survival) and R. sandwicensis (1% survival). All other 18 test plant species failed to support larval development. A risk analysis was conducted to quantify the acceptability of non-target species as host plants for H. hubrichi on the basis of the insect's performance at various stages in its life cycle. Risk of damage to all plant species tested was insignificant except for R. sandwicensis. Risk to this native plant relative to S. terebinthifolius was estimated at 1%. Currently this level of risk is too high to request introduction of this insect into the Hawaiian environment. Detailed impact studies in the native range of S. terebinthifolius are needed to identify the potential benefit that this insect offers. Also, field studies in South America with potted R. sandwicensis would give a more reliable analysis of the risk this native Hawaiian plant would face from natural populations of H. hubrichi. [ABSTRACT FROM AUTHOR]