Technical staff, Sophie Nyoni and Pritty Khumalo, have again produced millions of nematodes for the control of the Sirex woodwasp. The nematode, Deladenus siricidicola, are inoculated into Sirex-infested trees, where they parasitize the Sirex larvae and result in sterile female wasps emerging from inoculated trees. These sterilized female wasps subsequently spread the nematode to other Sirex-infested trees.

FABI has been mass rearing this biological control agent for many years. This year the nematode production has been very successful, with many flasks producing more than six million nematodes, far more than the average of one million per flask generally obtained.

The annual inoculation of nematodes is organized by the Sirex Co-ordinator, Mr Philip Croft. The first nematodes in 2021 were sent in February and the inoculations for the summer rainfall area will be finished by around the end of March. The Sirex woodwasp is one of the most serious pest threats to pine plantations and the biological control programme that has been implemented over many years has been key to its management.