Serpentine leafminer (Liriomyza huidobrensis; SLM) is a high-risk invasive pest of horticulture and vegetable production systems. It is known to attack and damage over 200 different plant species.
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.
Find out more about SLM biology and impacts.
SLM is classed as Prohibited Matter in Tasmania under the Biosecurity Act 2019.
Biosecurity Tasmania (BT) is currently investigating detections of SLM in North West Tasmania.
What we know
The first detection came after a concerned grower reported unusual insect activity on host plants to BT. Initial diagnostics indicated that the sample was likely SLM, with a high degree of confidence. Molecular testing results confirmed SLM on 23 June 2026.
As of 4 August 2026 there are three (3) sites in North West Tasmania where SLM has been detected. The additional sites were identified through delimiting surveillance undertaken by BT.
The most recent detection has been linked to an existing infested site and there is no known spread within the broader environment at this time.
SLM has been present on mainland Australia since 2020 and is considered established in New South Wales, Queensland and Victoria.
It is not currently known how or when SLM entered Tasmania, or whether there are any other populations here.
SLM is not notifiable under the national Emergency Plant Pest Response Deed (EPPRD) as it is considered established in Australia.
Biosecurity Tasmania undertook a rapid risk analysis when SLM was first detected in NSW. The analysis concluded that treatment options were not practical or cost-effective at the time, so there are no SLM-specific import requirements for hosts entering Tasmania.
BT has advice from the federal Department of Agriculture, Fisheries and Forestry that there are no international trade implications relating to this detection.
Domestically, the only jurisdiction that currently has import controls in place for SLM is Western Australia. Independently of the detection in Tasmania, WA has advised that it is updating its host lists for SLM. Growers should check with WA biosecurity authorities prior to exporting to that state.
What we're doing
BT is working with the impacted properties to manage the detections, with site-specific biosecurity directions in place to control and minimise spread.
BT is also investigating potential movements, including trace back/forward of stock to better understand the potential distribution of the pest.
BT will work with affected Tasmanian industries to determine actions to be taken following this detection.
What you can do
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.
 Serpentine leafminer leaf damage
Photo: NSW DPIRD
|  White squiggly tracks on a leaf surface caused by serpentine leafminer (Liriomyza huidobrensis) damage
Photo: Merle Shepard, Gerald R.Carner, and P.A.C Ooi, Bugwood.org
|
Due to the presence of other leafminers in Tasmania, BT is particularly interested in the following:
Heavy leafminer infestations on commercially grown plants, particularly if the infested plants have not been infested previously.
Infestations on plants that are not commonly attacked by other leafminers already present in Tasmania, including:
Aster sp. (e.g. daisies)
artichoke
Bellis perennis (lawn daisy)
beans
Calendula sp. (e.g. pot marigold)
carnation
celery
cucumber
coriander
Gladiolus sp.
Pumpkin
Ranunculus sp. (e.g. buttercups)
squash
sunflower
Tagetes sp. (e.g. marigold)
Verbena sp.
Viola sp.
zucchini
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 safely do so.
Report it to Biosecurity Tasmania: Phone: 1300 368 550; Email: biosecurity.tasmania@nre.tas.gov.au.
Wellbeing support
If you need assistance or support, please remember that help is always available. You can contact:
This is a 24/7 mental health support, triage, and referral phone line delivered by the Tasmanian Department of Health in partnership with Lifeline Tasmania.