First record of Closteroceruschamaeleon, parasitoid of the Eucalyptus Gall Wasp Ophelimusmaskelli (Hymenoptera, Chalcidoidea, Eulophidae), in the New World.

The uniparental parasitoid Closteroceruschamaeleon (Girault) is discovered to be fortuitously present on a population of the invasive Eucalyptus Gall Wasp Ophelimusmaskelli (Ashmead) in Riverside, California. This is the first report from the New World of Closteroceruschamaeleon, which has proven to be a highly effective natural enemy of Ophelimusmaskelli in the Mediterranean Basin. The taxonomy and identification of Closteroceruschamaeleon is discussed.