Reduced parasitism of Sirex noctilio in radiata pines inoculated with the nematode Beddingia siricidicola during 1974–1989

Summary

Artificial inoculations of radiata pines with the nematode Beddingia siricidicola from 1985 to 1988 have resulted in less than 30% of the emerging Sirex noctilio being parasitised by these nematodes. In contrast, the original inoculation procedure, developed in 1974, consistently produced greater than 95% parasitism. Because various components of the inoculation procedure have been changed since 1974, a study was started during 1989 to investigate the effects of gelatin concentration of the nematode carrier, of hammer type used to make inoculation holes, and of moisture content of the wood on parasitism rates by the nematode. Results indicated that these factors were not responsible for the low rates of parasitism. The infective capacity of nematodes produced in laboratory cultures needs to be investigated.