Tasmania Confirms First Detection of Invasive Serpentine Leafminer

Authorities are investigating Tasmania's first detection of the invasive serpentine leafminer. The high-risk pest affects horticultural and vegetable production systems, and has been present interstate since at least 2020.

The insect was found at a commercial grower in Tasmania's north-west. According to Biosecurity Tasmania, the species is known to affect more than 200 host plant species by damaging plant leaves and reducing their ability to photosynthesise, leading to reduced plant growth and lower crop yields.

Leafminers, including the serpentine leafminer (SLM), create tunnels in plant leaves as they feed, leaving distinctive squiggly white lines on the leaf surface. The site-specific directions to control and minimise spread were in place, and it was undertaking "surveillance and tracing activities".

The invasive pest damages the leaves of certain plants. (Courtesy: NSW DPIRD)

The serpentine leafminer (Liriomyza huidobrensis) is a leaf-mining fly. Its larvae feed by tunnelling through plant leaves, causing "mines". Major crop hosts include potato, beans, peas, brassicas, lettuce, celery, tomato and pumpkins and other gourds. It also attacks some ornamental plants.
 

Public asked to report

Biosecurity Tasmania reported that other leafminer species were "very common" in Tasmania, but accurately diagnosing the serpentine leafminer was only possible through rearing larvae through to the adult stage, or through molecular testing. It has urged the public to aid monitoring by reporting specific cases of leafminer sightings. 

 

Pupae of the serpentine leafminer

These include heavy leafminer infestations on commercially grown plants, particularly if the infested plants have not been infested previously, and leafminer damage on plants that are not commonly infested by the leafminer species already present in Tasmania. Those species include aster, artichoke, beans, calendula, carnations, celery, cucumber, coriander, gladiolus, marigolds, pumpkin, ranunculus, squash, sunflower, verbena, viola and zucchini.

A full list is available here