The end of October saw the first intentional introductions of the parasitoid wasp Quadrastichus mendeli. This wasp is a solitary parasitoid of the eucalypt gall wasp, Leptocybe invasa, a serious pest of eucalypts in South Africa and elsewhere in the world. Native to Australia, Quadrastichus mendeli was not intentionally introduced to South Africa, but was reported in the country in 2016, likely introduced with its insect host.

Results from the Forestry South Africa (FSA) funded National Leptocybe Monitoring Programme indicated that the distribution of Q. mendeli in South Africa remained limited. But, in areas where it was present, it had achieved high levels of parasitism in a short period, showing its potential to reduce populations of Leptocybe.

A strategy was thus developed to collect this parasitoid from sites where it was known to be present from the monitoring data and release these wasps in areas where they have not been reported. The first such releases were near Greytown, KwaZulu-Natal, but subsequent releases in other regions of the country are already planned.

It is hoped that these releases, together with the previously released biological control agent, Selitrichodes neseri, will contribute to the management of the eucalypt gall wasp.