Identification of the Diadegma species (Hymenoptera : Ichneumonidae, Campopleginae) attacking the diamondback moth, Plutella xylostella (Lepidoptera : Plutellidae)

The species of Diadegma that attack Plutella xylostella (Linnaeus) are revi sed. Following a morphometric study involving principal components and disc riminant analyses, seven distinct morphospecies are recognized. One species is described as new: D. novaezealandiae from New Zealand. Diadegma mollipl a (Holmgren) is the name for the species from sub-Saharan Africa and some I ndian Ocean and South Atlantic islands. Diadegma varuna Gupta syn. nov. and D. niponica Kusigemati syn. nov. are both synonymized with D. fenestrale ( Holmgren). Diadegma xylostellae Kusigemati is strongly presumed to be a syn onym of D. semiclausum (Hellen). An illustrated identification key is provi ded and each species is described in a standard way.