Recent FRuit Fly PaRasitoid intRoductions

Fopius ceratitivorus Wharton is the most recently imported parasitoid for biological control of tephritid fruit flies in Hawaii. In this paper we summarize current progress on studies of this parasitoid under quarantine conditions in Hawaii. Tests on its potential target host range reveal that F. ceratitivorus attacks and completes its development only in the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). The three other extant fruit fly pests in Hawaii, Bactrocera cucurbitae (Coquillett), Bactrocera dorsalis (Hendel) and Bactrocera latifrons (Hendel) are unsuitable for F. ceratitivorus development. Competition studies with the well-established and dominant fruit fly parasitoid, Fopius arisanus (Sonan), showed that either species can win in intrinsic competition with each other, depending on which one occupies the host first. In both choice and no-choice tests, F. ceratitivorus was found to cause no parasitism nor mortality to eggs or larvae of the non-target tephritid Procecidochares alani Steyskal on infested pamakani weed, Ageratina riparia (Regel); nor the native Hawaiian tephritid Trupanea dubautia (Bryan) infesting flower heads of the endemic Asteraceae shrub, Dubautia raillardiodes Hillebrand. These findings suggest that release of this parasitoid as a biological control agent in Hawaii will pose minimal non-target risk and may contribute to overall fruit fly biological control in the islands. The delays due to the regulatory bureaucracy in removing the wasp from quarantine following host range testing are also discussed.