RD&E program for control, eradication and preparedness for vegetable leafminer (MT16004)
What’s it all about?
Beginning in 2017, this multi-industry project was originally established to bolster preparedness for and protection against the potential spread of vegetable leafminer (Liriomyza sativae) through Australian growing regions. The pest is capable of infesting a broad range of crops and was first detected on the country’s mainland in 2015, in a backyard garden in the Cape York Peninsula community of Seisia.
In late 2018 the project's work was expanded to also cover two additional leafminers: American serpentine leafminer (Liriomyza trifolii) and serpentine leafminer (Liriomyza huidobrensis).
Specific project activities include developing information and resources for monitoring, managing and eradicating leafminers; identifying and modelling the spread of the pests; reviewing and looking at accessibility of chemical and biological control options; and generally increasing awareness and understanding of the leafminers in the relevant industries and in the community.
In 2019, this project’s scope was broadened to add potato leafminer (Liriomyza huidobrensis) and American serpentine leafminer (L. trifolii) to the work already being done on vegetable leafminer (L. sativae) (VLM).
The team have continued to progress its efforts across all program areas.
The VLM contingency plan is nearing completion, with two additional plans for potato leafminer and American serpentine leafminer drafted.
Distribution mapping and surveillance guidelines
During May 2019, field surveys within the Northern Peninsula Area and Cairns found no evidence of leafminers. As such, there is no confirmed spread of VLM outside the known range. The interactive mapping tool for leafminer distribution can be accessed here.
The project team increased its understanding of VLM impact, considering vulnerable commodities, climate-based establishment risk, seasonality and human-assisted dispersal pathways.
A surveillance guideline was developed by the team. It seeks to maximise detection success while balancing the need to cover area with the need to spend sufficient time.
Biocontrol information package
An information package that addresses both biological and chemical control options was drafted, and the review on mass-rearing techniques is nearing completion.
Emergency use permit applications
Six insecticide permits were applied for to the APVMA for the control of leafminers in Australia.
Several communication materials were developed including an article about VLM surveillance in Torres Strait and Cape York Peninsula, published in Vegetables Australia magazine. Workshop summaries and leafminer awareness information was published as AUSVEG Weekly Update articles, and the leafminer awareness flyer was updated.
The team conducted workshops and gave presentation in Atherton, Bundaberg, Mornington Peninsula, Werribee, Bowen, Ayr and Greater Sydney, with additional awareness raising activities in Virginia and Devonport. A second Cape York Peninsula extension and engagement visit was also made.
Research information and project updates were also shared on the vegetable leafminer webpage and via social media.
Watch InfoVeg TV Episode 15 which asks: Have you seen the vegetable leafminer? (5 mins)
Download this vegetable leafminer flyer designed to raise industry and community awareness
Access the interactive leafminer distribution map on cesar’s website
Read articles about:
- Vegetable leafminer under the microscope in far north Queensland on pages 30-31 of the July / August 2019 edition of Vegetables Australia
- Serpentine leafminer: A threat to the potato industry on page 28 of the February / March 2019 edition of Potatoes Australia magazine
- A surveillance toolkit in development for detecting vegetable leafminer published on the cesar Australia website, March 2019.
The project team reports progress on all fronts, including…
The draft plan is further advanced, now including surveillance and diagnostic information.
Following an engagement and extension mission in the Torres Strait and Northern Peninsula Area, a scoping study report now provides insights into key biosecurity risks and transmission pathways.
Results from the 2018 surveys in northern Australia have been added to the interactive VLM portal as well as information on seasonal activity of affected commodities. Regional information on crop seasonality and VLM seasonality can be accessed by clicking on any location in the map. Access the interactive mapping tool for leafminer distribution here.
Further mapping has been done of potential VLM parasitoid species to find out the type of climates they can live in. The team has found that one parasitoid is widely distributed in Australia, from the Torres Strait down to southern Victoria and across highly diverse plant families (grasses to broadleaf plants), making it even more promising as one of Australia’s valuable natural resources for managing VLM.
Investigation of mass-rearing techniques for biocontrol species
The team has added to the initial biocontrol review, focusing on details of specific protocols for rearing and quality control used overseas, together with discussion of methods needed to evaluate the potential of parasitoid species other than Diglyphus isaea.
Applications for emergency use permits
Plant Health Australia has submitted applications to the APVMA for pre-emptive permits to use chemicals in case the pest spreads further.
A workshop was held in conjunction with VegNET and NT Farmers in greater Darwin, Northern Territory. The project team gave an introduction and update on activities that have occurred since the commencement of the project and discussed the importance of this project to industry.
AUSVEG undertook three farm visits in Lake Bennett and Marakai, where major crops included okra, cucumber, chilli, and bitter gourd, to tell them about the pest and the project. Time was also spent gathering surveillance information from growers to assist the development of a toolkit for proof of area freedom surveillance.
Articles about the research, found in the ACT NOW section below, were publicised further through Facebook and Twitter.
Updates have been made to the project summary flyer and to the vegetable leaf miner webpage.
Read the 47 page scoping report Cape York & Torres Strait Biosecurity which includes pest transmission pathway risks for Australian horticultural industries and suggests methods to support continuing engagement in the region for the purpose of reducing the risk of exotic pest spread to production regions.
The project has been continuing to develop ways to detect and diagnose vegetable leafminer, plant for potential incursions, and raise awareness of the pest among industry and the community. Below are just some of the research team’s recent activities:
- Contingency plan. The project has completed its first draft of a contingency plan for vegetable leafminer, which will be reviewed and updated as the project progresses.
- Scoping study. In May 2018, the project team completed an engagement and extension mission in the Torres Strait and Northern Peninsula Area. Findings from the tour will culminate in a scoping study report that will guide future industry engagement, provide insights into key biosecurity risks and transmission pathways and make recommendations for mutually beneficial collaboration between the horticulture industry and far northern communities, for the purpose of better biosecurity.
A significant outcome of this study was the identification of a parasitoid wasp species that is responsible for helping to control vegetable leafminer populations in the area. These species are a key focus of parasitoid surveillance efforts within the rest of Australia, as well as during parasitoid distribution modelling. This information will support the development of future integrated pest management plans.
A survey conducted in the area also indicated that the pest has not spread further south than its known range in Seisa.
- Completion of a surveillance toolkit. The project team has conducted three major experiments to support the development of draft surveillance toolkits – one for the vegetable industry, including growers, and one for government agencies responsible for exotic pest incursion responses. These will be made available when finalised and will continue to be updated as the project progresses.
- Continuation of mapping leafminer distribution. The project team have developed an interactive online tool available here, which includes vegetable leafminer distribution maps (including absence records), host plant distributions (weeds and cultivated crops), parasitoid distributions, plus leafminer establishment risk predictions and spread risk predictions. The map is currently being used to assist the development of tools and guides for industry.
- Community engagement. The project team continues to engage with industry to ensure that growers are ready and able to track the spread of the disease and identify new incursions. Watch an animated infographic that was designed to inform growers and raise awareness in the community about the threat of vegetable leaf miner. Other outputs have included several articles for the levy-funded industry magazine Vegetables Australia that you can access via the ACT NOW section below, engagement with interested parties at a trade stand at Hort Connections 2018 and continued distribution of the project’s awareness poster and flyer to growers, councils, schools and tourism hotspots in at-risk regions.
Three workshops were also held in Victoria in March, April and May in partnership with the levy-funded VegNET program. Attendees were provided with background information on vegetable leafminer, an introduction to the project activities and aims, an overview of progress and an explanation of how outputs will benefit industry members.
Read two articles in the Vegetables Australia magazine about vegetable leafminer:
- Community gardens provide surveillance and sampling opportunities for vegetable industry on page 32 of the March/April 2018 edition
- Enhancing future preparedness for the vegetable leafminer on page 56 of the July/August 2018 edition.
The project has been busy producing educational resources for industry and the community, which to date include…
- A soon-to-be-released video for growers and the public, addressing the threat from vegetable leafminer and the project’s aims
- This podcast from InfoVeg Radio, which includes information on the pest and how to report possible detections
- This project info flyer (circulated in earlier editions of Hortlink)
- This awareness poster, which is being distributed to local councils, schools and throughout tourism hotspots in at-risk regions
- A resource for school educators, currently in development and designed to talk to primary school children about exotic pests, with a focus on vegetable leafminer.
For industry, in-person updates at industry workshops and nursery visit continue, while engagement with local council contacts is also ongoing to ensure council officers in at-risk regions are equipped with information – particularly to guide the assessment of non-commercial host plants during weed surveys. This information also has the potential to be integrated in to council biosecurity plans.
Meanwhile, the project partners are continuing to work towards the development of vegetable leafminer surveillance toolkits. This includes looking at the most successful and efficient surveillance techniques for the pest, with fieldwork being undertaken to assess pest monitoring methods from around the world. Initial work was conducted on the use of yellow sticky traps, with the focus now shifting to visual surveillance techniques as the method most likely to yield success for early detections of leafminer. Look for updates on this work as the project progresses.
Other ongoing work includes…
- Development of molecular identification methods, including investigation of the potential to extract and identify DNA from empty leafmines.
- Development of an interactive distribution map of the pest.
- Development of a leafminer establishment model, with the team looking at factors and conditions influencing incursion risk and where the species is next likely to occur, to more effectively and efficiently deliver management responses.
- Bringing together information on biological control options, using existing research from Australia and internationally to identify key parasitoid species that could be involved in the control of vegetable leafminer in both open-air crops and glasshouses, as part of an integrated pest management approach. Other biological control components being used or researched overseas, including the use of beneficial fungi and sterile insect technology, are also being reviewed.
- Looking at chemical control options, bringing together information in preparation for applications for appropriate emergency use permits.
Back in July, the project team undertook their first field surveys for vegetable leafminer, on Thursday Island and the Northern Peninsula Area in Far North Queensland. This work identified two new host plant species for the pest, and resulted in the collection of larvae, pupae and adults from a range of commercial and non-commercial hosts for use in lab work. Preparation for 2018 field surveys is now underway.
The researchers have also been looking at pest monitoring methods from around the world, including the use of yellow sticky traps, pupa pan trapping, visual surveys and the use of plant volatiles as lures. The team has noted that many surveillance techniques rely on the development of rapid and efficient methods for processing and screening bulk samples for traces of the target species, and work is being conducted to this end – with the team beginning to develop molecular identification methods for vegetable leafminer. They are also looking at the ability to detect the pest from DNA left behind in mine damage on plants.
If you missed it in other channels, download this project awareness flyer for a quick project summary. You can also see a project overview – including key info on vegetable leafminer – in the article from p12 in the November/December 2017 edition of Vegetables Australia magazine.