BIOSECURITY UPDATE: Serpentine leafminer

Thursday, 19 November 2020

Detected infesting field-grown vegetables in western Sydney in October, Serpentine leafminer has now been found across several horticultural cropping systems including production nurseries in the Greater Sydney area.

New South Wales Department of Primary Industries (NSW DPI) and Greater Sydney Local Land Services (GS LLS) are mounting a response to delimit the current distribution, with the aim to eradicate, or contain and control this pest.

Greenlife Industry Australia (GIA) has also been working with the Australian Pesticide and Veterinary Medicines Authority (APVMA) to secure a Minor Use Permit (MUP) PER88977, for the management of leafminers including Serpentine leafminer (SLM).

To maintain pesticide efficacy, it’s critical that production nurseries apply an integrated approach to managing this pest, including:

  1. Identify susceptible host species and aggregate where possible in growing areas, to allow for effective and efficient resource allocation for management. Host list can be found here.
  2. Engage in regular, structure crop monitoring processes to identify the presence, location and density of this pest. BioSecure HACCP crop monitoring procedures and recording templates can be found here.
  3. Implement a yellow stick trap program across susceptible host ranges, and regularly inspect. BioSecure HACCP stick trap procedures and recording templates can be found here.
  4. Ensure you have an effective and consistent weed management program in place to limit reproduction and reinfestation opportunities, as weeds are a common host of Serpentine leafminer. BioSecure HACCP site surveillance procedures and recording templates can be found here.
  5. Use a robust pest identification resource to make sure that the correct identification is being made when undergoing crop monitoring or inspecting sticky traps. Pest ID Tool can be found here.
  6. Select appropriate insecticides for a rotation program and follow the MUP directions on application rate and on the number of applications per treatment cycle. Each treatment cycle must be complete before must be completely applied before moving on to the next active ingredient in the rotation plan. Access PER88977 here.

It’s critical that production nurseries managing this pest have a clear pesticide rotation program in place, preferably based on a minimum of three different active ingredients from three different mode of action groups.  Growers can add more active ingredients into rotation if required however any additions must be from a different mode of action group to minimise pesticide resistance within the population.

Table 1. Examples of Serpentine leafminer Pesticide Rotation Programs

If you detect any signs of leaf mining in vegetables, please contact the Exotic Plant Pest Hotline on 1800 084 881 right away – early detection is vital for managing and eradicating pests and disease.

The ‘National Nursery Industry Biosecurity Program’ (NY15004) project is funded by Hort Innovation using the nursery levy and additional funds from the Australian Government.