During 1979, cocoons of the ichneumonid Sphecophaga vesparum burra (Cresson), a parasitoid of some Vespinae, were imported from Washington State, USA to New Zealand. Two adults and four cocoons raised in quarantine on Vespula gemanica (F.), the German wasp, were field released, but there was no evidence of establishment. Subsequent imports of S. vesparum vesparum (Curtis) from Europe were propagated mainly on the recently immigrant V. vulgaris (L.), the Common wasp. Thirteen generations of S. v. vesparum were raised by July 1985, and all stages of the parasitoid were released into wasp nests in Canterbury. Six of seven V. vulgaris nests and three of six V. germanica nests were parasitised. none