AN OUTBREAK OF SIREX NOCTILIO F. IN TASMANIA

Abstract

In recent years Australia has imported considerable quantities of soft wood timber, a proportion of which has been found to be infested with various species of siricid wasps. In view of the difficulties associated with the adequate inspection of such imports by quarantine officers it is not surprising that one species, Sirex noctilio F., which has been in New Zealand for many years, has now become established in a plantation of Pinus radiata in Tasmania. The location and history of the Pittwater plantation is given together with details of the known distribution of the insect within the area. The life cycle of the insect in Tasmania would appear to be similar to that reported in New Zealand, i.e. 1–2 years. From the available information it appears that the insect gained entry not later than the summer of 1950/51, but this may have occurred earlier. Although an unidentified fungus has been found in association with S. noctilio in Tasmania the rapid and extensive wood rotting reported from New Zealand has not been observed. The presence of S. noctilio may introduce a new factor into plantation management in Tasmania.