none Listronotus bonariensis; HYMENOPTERAN-PARASITES; Microctonus hyperodae; Parasite phenology; NEW-ZEALAND; Hymenopteran parasite phenology, prospective model Microctonus hyperodae; LIFE-CYCLE; COLEOPTERAN-HOSTS; Listronotus bonariensis; Parasite phenology; NEW-ZEALAND; Phenology, prospective model, coleopteran host A predictive phenological model is described for the parasitoid Mictoctonus hyperodae, introduced to New Zealand as a potential biological control agent against Argentine stem weevil Listronotus bonariensis. The model is based on development/temperature relationships obtained from experiments on the parasitoid in quarantine prior to its release, allowing early predictions of its phenology in different parts of the target pest's New Zealand range. In particular the model was used to predict the number of parasitoid generations each year, the degree of temporal synchrony between parasitoid adults and the susceptible adult pest stage, the order of parasitism and reproduction in the pest's life cycle as a possible basis for a simplified, discrete host/parasitoid population model, and the likely significance of ecotypic differences in development and diapause characteristics of the parasitoid. These applications demonstrate the potential for simple models to help in climate matching of classical biological control agents and estimation of their interaction with pest dynamics, using data obtainable prior to their introduction and release, in addition the model proved useful as a decision aid during the release programme, by indicating the likely effects of unusual weather and the need or otherwise for further parasitoid releases.