Oncastichus goughi Headrick and Lasalle
Taxonomic placing: Insecta, Holometabola, Hymenoptera, Chalcidoidea, Eulophidae.
Common name: Geraldton wax wasp.
Geographical distribution: Australia, California and in Israel since the 1990’s.
Host plants: The cut-flower crop Chamelaucium uncinatum Schauer (Myrtaceae) (wax flower).
Morphology: The adult wasps are black, about 1-2 mm in length
Economic importance: A major pest of Geraldton wax, Chamelaucium uncinatum (Myrtaceae) (wax flower). It induces galls and plant deformations, rendering the cut-flower crop as well as the foliage unmarketable.
Life cycle: The eggs are placed within the host plant and the larvae develop in young leaves and stems, inducing the formation of galls and other deformations. Pupation takes place within the gall, the adult boring a round hole through which it emerges. Catches in traps suggest that the pest raises two annual, overlapping generations.
Management
Monitoring: Green and yellow sticky traps can be used to monitor the pest.
Cultural control: The early wax flower cultivars that bear smaller leaves are less susceptible to the pest.
Chemical control: Avermectins and imidacloprids, applied as systemics greatly reduce the pest’s damage.
References
Ben-David, Z., Ofer, Y., Kedar, J., Schachner, T and Zaidan, M. 1997. Control of the gall wasp Oncastichus goughi, a new pest of wax flowers. Avivon 32: 14-16 (in Hebrew).
Ben-Yakir, D. (and 7 co-authors). Biology and control of a gall-forming wasp, a new pest of Geraldton wax plant in Israel. Phytoparasitica 25: 145-146.
Headrick, D.H., LaSalle, J. and Redak, R.A. 1995. A new genus of Australian Tetrastichinae (Hymenoptera, Eulophidae), an introduced pest of Chamelaucium uncinatum (Myrtaceae) in California. Journal of Natural History 29: 1029-1036.
Redak R.A. and Bethke, J.A. 1995. Detection and seasonal occurrence of gall-forming wasps (Hymenoptera, Eulophidae) on Geraldton wax plant. Journal of Economic Entomology 88: 387-392.