Review of Australian species of Megastigmus (Hymenoptera: Torymidae) associated with Eucalyptus, with descriptions of new species.
The species of Megastigmus Dalman 1820 (Hymenoptera: Chalcidoidea: Torymidae), related with Eucalyptus species (Myrtaceae) from Australia were reviewed. A total of 33 species of Megastigmus were studied, with nine species described as new: chrisburwelli, erolhasani, judikingae, lawsoni, leptocybus, rieki, thailandiensis, thitipornae, zvimendeli. Three new synonymies are created: adelaidensis Girault syn.new=maculatipennis Girault, ater Girault syn.new=tasmaniensis Girault, trisulcus Girault syn.new=voltairei (Girault). All species were described in detail, with photographs of their diagnostic characters and available biological data provided. Some new diagnostic characters of the genus were found and added to the generic diagnosis of earlier authors. An identification key is provided for the treated Megastigmus species. Species of Megastigmus were recorded as parasitoids of the gall inducer insects or as a gall inducer in several parts of plants.