Tetrastichus species (Hymenoptera, Eulophidae), parasitizing the elm-leaf beetle Pyrrhalta luteola (Müll.) and allied hosts

Abstract

A historical review is given of Tetrastichus gallerucae (Fonscolombe), an important Chalcidoid parasite of the elm-leaf beetle, Pyrrhalta luteola (Müller). To facilitate its identification, a revision of all the European Tetrastichus species parasitic on Pyrrhalta luteola and Galeruca (Coleoptera, Chrysomelidae) is presented. These species fall into two groups, those of gallerucae (Fonsc.) and suevius (Walker). A diagnosis of each of these groups is given, followed by keys to their females and males. A full redescription of gallerucae is included and a neotype is designated for this species. Two new European species of the gallerucae-group are described.