In March and October 2022, a team of scientists from Agriculture Victoria Research undertook field work to identify plant pests and diseases across several disciplines: entomology (insects), fungal plant pathogens, nematology, bacterial and viral plant pathogens, and weeds. Working under the guidance of the Norfolk Island community, the team collected more than 1,000 samples for further examination.
The key findings of the survey include:
- Records of many insect species not previously reported in Norfolk Island. This includes endemic psyllid species, beneficial insect species, and pest species.
- No exotic fungal pathogen detections.
- Records of 12 species of plant-parasitic nematodes, all previously recorded on Norfolk Island.
- No detections of exotic plant pathogenic bacteria.
- Records of 16 virus species previously not reported in Norfolk Island including Southern tomato virus and Watermelon crinkle leaf-associated virus 2.
- Seven new records of weeds or plants naturalised on Norfolk Island.
The report noted:
- Newly identified insect pests were generally recorded in very low numbers.
- The newly identified insect pests include: aphids, a psyllid, a thrips, a moth and a termite. These are not National Priority Plant Pests. It is not known how or when they arrived on Norfolk Island.
- The Southern tomato virus and Watermelon crinkle leaf-associated virus 2 have a limited host range and Southern tomato virus is not associated with disease. The impact on the remaining 14 virus species should not be a cause of concern.
- Of the seven new records of weeds, Bitou bush and Agapanthus are known to be troublesome weeds. Bitou bush is currently limited to a single location on Norfolk Island and Agapanthus were found in one public reserve. Of the remaining five weed species identified, only Indian siris has weedy potential, although it seems that the single specimen present on island does not produce seed.
The report made several management recommendations:
- Undertake periodic pest surveillance for Norfolk Island.
- Develop a database of the Norfolk Island genetic diversity.
- Develop a morphological voucher/tissue collection of Norfolk Island diversity.
- Involve the Norfolk Island community in biosecurity activities.
- Include permits to collect live specimens for any future fungal plant pathogen surveys.
- Develop a Norfolk Island weed management prioritisation process.
The relevant government agencies are considering the recommendations best suited to the needs on island.
This project was funded by the Department of Infrastructure, Transport, Regional Development, Communications, and the Arts. Support was provided by The Department of Agriculture, Fisheries and Forestry and Norfolk Island Regional Council.