APVMA decision on paraquat and diquat
23 June 2026
Biosecurity Tasmania (BT) is investigating a detection of serpentine leafminer (Liriomyza huidobrensis; SLM) in North West Tasmania.
Serpentine leafminer is a high-risk invasive horticultural pest which can damage over 200 different plant species. This is the first detection of Serpentine leafminer in Tasmania, the pest has been present on mainland Australia since 2020 and is considered established in NSW, QLD and VIC.
Initial diagnostics indicated that the sample was likely SLM with molecular testing results confirming SLM on 23 June 2026. It is not currently known how or when SLM entered Tasmania, or whether other populations are present. SLM is classed as Prohibited Matter in Tasmania under the Biosecurity Act 2019.
Biosecurity Tasmania is working with the impacted grower to manage the detection and investigate potential movements. BT is working with affected Tasmanian industries to determine actions to be taken following this detection.
Growers and members of the public should look out for distinctive squiggly white lines on plant leaf surfaces caused by feeding damage from leafminer larvae.
Due to the presence of other leafminers in Tasmania, reporting should be prioritised to the following cases:
- Heavy leafminer infestations on commercially grown plants, particularly if the infested plants have not been infested previously.
- Plants with leafminer damage that are not commonly infested by leafminer species already present in Tasmania.
If you see leafminer damage on these plants, or suspect possible SLM:
- Restrict access to the area and don’t move any plants or plant material off-site.
- Note the location and get a photo of the damage and leafminers if you can.
- Report it to Biosecurity Tasmania: Phone: 1300 368 550; Email: biosecurity.tasmania@nre.tas.gov.au
If you see anything unusual, call the Exotic Plant Pest Hotline: 1800 084 881
Further Information: