The white peach scale, Pseudaulacaspis pentagona, was first recorded in Hawaii in 1997 and since then became a serious pest of papayas in most papaya fields in East Hawaii Island. The parasitoid, Encarsia diaspidicola, was successfully used in the biological control of the white peach scale on passion fruit in Samoa. E. diaspidicola was collected in Samoa in 2006 and a colony was established in the quarantine facility at Hawaii Volcanoes National Park. We hope to release this wasp in papaya fields if the host specificity testing results suggest that the wasp has a narrow host range and will not pose a threat to endemic scale insects. Several non-native diaspidid scales and one endemic scale, Colobopyga pritchardiae (Halimococcidae), (first recorded on the island of Hawaii by us), were tested in no-choice and choice tests. No evidence of parasitism of any of the tested non-target species was found so far suggesting that E. diaspidicola has narrow host range.