Quadrastichus

Kim, Il-Kwon, Mendel, Zvi, Protasov, Alexey, Blumberg, Daniel & Salle, John La, 2008, Taxonomy, biology, and efficacy of two Australian parasitoids of the eucalyptus gall wasp, Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae: Tetrastichinae), Zootaxa 1910, pp. 1-20 : 5-6

Genus Quadrastichus

Quadrastichus was described by Girault (1913[167]), and synonymised with Aprostocetus by Bouček (1988). It was subsequently removed from synonymy by Graham & La Salle (1991), and given revised status as a senior synonym of Cecidotetrastichus Kostjukov. Generic keys which would allow identification to Quadrastichus are provided by Graham (1987 as Cecidotetrastichus ; 1991), La Salle (1994), and Schauff et al. (1997). A complete synonymy list for Quadrastichus is given by Graham (1991).

Many species of Quadrastichus are associated with galls, usually as endoparasitoids of Diptera Cecidomyiidae and Hymenoptera Cynipidae , and one European species Q. sajoi (Szelényi) has larvae which are predatory on eriophyid mites within galls (Graham 1991; La Salle 1994; Noyes 2003). One species has recently been recorded as an invasive pest which induces galls on coral trees ( Erythrina spp.: Fabaceae ) ( Kim et al. 2004).

In addition to being associated with galls, species of Quadrastichus have varied biologies, and other hosts include Coleoptera Curculionidae and Buprestidae (Graham 1991; La Salle 1994; Noyes 2003), and several Asian species are parasitoids of leafmining Agromyzidae ( Reina & La Salle 2003, 2004).

Although at this time, there are only two Australian species recognized in the genus Quadrastichus (nigrinotatus Girault, mendeli sp.n.), results from surveys indicate that there may be many more species in this genus associated with galls on Eucalyptus.