Woodchip sampling for the nematode Deladenus siricidicola and the relationship with the percentage of Sirex noctilio infected

Nematode levels were assessed for woodchips taken from sirex-infested trees in South Australia during July 1988. These trees were sampled to determine the percentage of sirex infected with nematodes that emerged during January to April 1989. A logistic equation was fitted to the data from 20 trees to quantify the relationship between the nematode level for woodchips and the percentage of sirex infected with nematodes. Knowledge of this relationship will allow an assessment of the nematode level in a plantation immediately before the inoculation period. Managers can prescribe nematode inoculations based on these results. An operational procedure for woodchip sampling is suggested. However, further testing is needed to verify the relationship in other regions and to determine a reliable period for sampling.