ABSTRACT Thaumastocoris peregrinus has become a major pest in eucalyptus. The most promising control method is the use of the parasitoid, Cleruchoides noackae , but little is known about its biology. Thus, the aim of this study was to investigate the oviposition behaviour of C. noackae in T. peregrinus eggs laid on strips of paper towel in the laboratory. 12 copulated females were placed in a plastic petri dish containing five T. peregrinus eggs and their behaviour was observed for 30 min/female. Several behavioural events were performed: searching for the host, host evaluation, insertion of the ovipositor, internal recognition and oviposition. Time elapsed between the insertion of the ovipositor and its removal varied from two to ten minutes. Learning more about C. noackae biology is very important to understand the dynamics between the parasitoid and its host, aiming at its biological control.