This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

A range of pests caused significant losses to the macadamia industry. There was a need to improve pest management by using Integrated Pest Management (IPM), and approach which incorporated sustainable management options for the complex of key pests.

During this study the researcher developed a new IPM strategy that included insecticide screening for fruitspotting bugs (FSB), macadamia lace bugs and banana fruit caterpillar, a pest of macadamias in Bundaberg. The researcher further investigated the potential of alternative FSB host plants as monitoring tools or trap crops, and investigated a parasitic fly as a potential biological control agent. Heat treatments used for nut drying at the time were also evaluated for their effectiveness in killing nut in shell pests, which remained a quarantine issue for export.

Our research identified a new chemical compound and a plant extract as the most effective alternatives to endosulfan in controlling FSB. Lepidex® gave mixed results; good control in the laboratory tests but not successful in the field. Actara® and the new chemical compound also effectively controlled macadamia lace bug and offered an effective alternative to endosulfan. Lannate® appeared to be the most effective control option for banana fruit caterpillar. The shrub Murraya paniculata was particularly effective in attracting FSB and had potential as a monitoring tool and trap crop. A parasitic fly had some potential for biological control of FSB. Temperatures of 50ºC killed larvae and pupae of pests in nut in shell.

Lepidex® was an alternative to endosulfan for FSB control, but low pH of spray solution was important. Lannate® at 2ml/L could have been used for management of banana caterpillar. In relation to postharvest pests, the macadamia nut-in-shell drying regimes used at the time were sufficient to kill macadamia pest species in nut in shell.

A better monitoring tool (i.e. trap hedge and pheromone trap) for FSB was needed for more targeted management. Alternatives to endosulfan still required further testing for future registration applications. Biological control for FSB needs to be further investigated. Other pests such as macadamia lace bug, banana fruit caterpillar, felted coccid and scirtothrips also needed to be considered in a holistic approach.