Synchronisation of the parasitoid Centrodora scolypopae with its host Scolypopa australis

Eggs of the univoltine passionvine hopper Scolypopa australis Walker (Homoptera Ricaniidae) are parasitised by Centrodora scolypopae Valentine (Hymenoptera Aphelinidae) The life cycle of the parasitoid and synchronisation with its host was studied in a gully near Hamilton over four years The parasitoid was usually univoltine overwintering in diapause as a prepupa and pupating when host adults were present in midsummer However above average summer temperatures in 1981 resulted in up to 60 of the parasitoid population on a sunny slope with a NE aspect pupating before winter demonstrating that the diapause was facultative Photoperiod was found to be a key factor in diapause maintenance