Serpentine leafminer (Liriomyza huidobrensis; SLM) is an invasive pest of horticulture and vegetable production systems that is now wide-spread on mainland Australia.
SLM was first detected in Tasmania in June 2026. Following this, Biosecurity Tasmania set up a response to explore how best to deal with this pest, with potential options including eradication and long-term management.
There is no health risk to people from SLM and produce damaged by SLM is safe to eat. You should always follow good hygiene practices, including hand washing, when handling and preparing food.
What is happening?
Tasmania is transitioning to long-term management of SLM.
Transition to management (T2M) focuses efforts on providing growers with the advice, tools and support needed to manage this pest in Tasmanian conditions.
Based on current evidence and expert advice, this approach will deliver the best long-term outcomes for growers and the broader industry.
Why is transition to management the best approach for this pest?
Following the detection of SLM in North West Tasmania, Biosecurity Tasmania undertook extensive surveillance, tracing and technical assessments to better understand the extent of the pest in Tasmania.
Based on current evidence, expert advice, and consultation with industry, eradication is not technically feasible because:
Eradication is only possible when a pest is contained and can be effectively treated. SLM can be difficult to detect when numbers are low.
SLM has been found at several locations across North West Tasmania, including sites that have no known connection to each other.
SLM is breeding on unmanaged host weeds. This means it is likely spreading in the environment, making it much harder to contain.
SLM can survive and reproduce on a wide range of crops and common weeds found in Tasmania.
Conditions across Tasmania are very suitable for SLM to establish, survive and spread.
Attempts to eradicate SLM in New South Wales, Victoria and Queensland were unsuccessful. In each case, authorities eventually moved from eradication to long-term management of the pest. This is also the case overseas.
Industry stakeholders have indicated a need for timely decision-making to support business planning and preparedness.
A T2M approach will allow resources to be focused on supporting growers.
What will happen next?
BT will complete its response activities in the next few weeks. Once completed:
Tasmania’s Chief Plant Protection Officer will revoke SLM as Prohibited Matter under the Biosecurity Act 2019. This will be published in the Tasmanian Government Gazette.
There will no longer be a legal requirement to report suspected SLM to Biosecurity Tasmania. Anyone concerned about unusual insect activity or crop damage is still encouraged to contact Biosecurity Tasmania.
Site-specific biosecurity directions issued during the response will be revoked. These were put in place during the response to help control and minimise spread from affected sites.
There will be no ongoing zoning or movement controls for SLM, reflecting a greater emphasis on prevention and shared responsibility. Growers and landholders can play a key role by maintaining good farm biosecurity practices and meeting their obligations under the General Biosecurity Duty, helping to protect agricultural production and reduce the pest's impact.
The transition will be implemented over a 12-month period, with Biosecurity Tasmania, AgriGrowth Tasmania, the Tasmanian Institute of Agriculture (TIA) and industry stakeholders working collaboratively to build industry capability and establish a sustainable long-term management framework.
This will include:
working closely with affected industries;
providing ongoing market access information and support;
support for grower education and extension activities.
Support for growers
SLM is a pest that can be effectively managed.
TIA will lead a research, extension and industry support program to assist growers and affected industries with long-term management of SLM.
This program will include:
Tasmania-specific guidance materials;
webinars and industry briefings;
information on distribution, monitoring and management;
integrated pest management (IPM) advice; and
research to improve understanding of SLM and natural biological control in Tasmania.
Market access
Market access remains a priority. Western Australia is currently the only Australian jurisdiction with specific import requirements for SLM host material.
WA requirements apply to host species with leaves – this includes leafy vegetables, herbs, cut flowers and foliage. Nursery stock must already meet existing import requirements for WA. Growers should check with WA biosecurity authorities prior to exporting to that state.
Biosecurity Tasmania will continue to provide updates and support to industry.
What growers can do to help manage SLM
For most growers, day-to-day farm operations will continue as normal. However, T2M does not reduce the importance of good property biosecurity.
Growers should continue monitoring crops, maintaining good farm biosecurity and managing pests as part of normal farming operations.
Adult leafminers are typically poor fliers, moving only short distances between crops. The main risk for spread is through people moving infested plant material and high-risk inputs (e.g. mulch, fill, growing media etc.).
To reduce the risk of SLM spreading, or being introduced onto their property, growers should:
avoid moving potentially infested plant material;
maintain good farm biosecurity practices;
monitor crops and host plants regularly;
manage host weeds;
clean machinery, equipment, vehicles and boots between properties.
Wellbeing support
Alongside the practical information and support being provided through government, research and industry, wellbeing support is also available.
If you need assistance or support, help is available through organisations such as Rural Alive and Well (RAW - 1800 729 827; www.ruralaliveandwell.com.au), your industry representative body, or other local support services. Reaching out for support is a positive step, and help is always available.
More information
For more information visit the Biosecurity Tasmania website (www.nre.tas.gov.au/SLM) or contact Biosecurity Tasmania on 1300 368 550.