In early 2021, a multi-industry project was established to examine the potential of endemic parasitoids of fall armyworm and deliver extension material to growers on how to effectively manage the pest. Project Lead and DAF Senior Entomologist Dr Siva Subramaniam spoke to Vegetables Australia and outlined the team’s activities so far, and how this research will ultimately benefit the Australian horticulture industry.

Fall armyworm (FAW) was first detected in early 2020 in far-north Queensland. It has quickly spread to several locations in Queensland, Western Australia, the Northern Territory and New South Wales.

Within a short period from the initial detection, significant crop damage (up to 80 per cent) was recorded in organic and conventional sweet corn crops and the pest has become a major concern for other vegetable crops. The rapid rise in FAW numbers and the high use of pesticides to manage the pest are a major threat to the existing Integrated Pest Management practices adopted by the vegetable industry.

A project was established in early 2021 to examine potential parasitoids of FAW and deliver extension materials to growers on how to effectively manage the pest.

Project team members are located in key production areas of QLD, WA and NT, and are from the Queensland Department of Agriculture and Fisheries (DAF), the Western Australian Department of Primary Industries and Regional Development, and the Northern Territory Department of Industry, Tourism and Trade.

Identifying potential parasitoids of the fall armyworm, Spodoptera frugiperda, and the risk to Australian horticulture (MT19015) is a multi-industry strategic levy investment under the Hort Innovation Melon, Nursery, Sweetpotato, Turf and Vegetable Funds.

Project objectives

Fall armyworm larvae feeding damage in sweet corn cobs.

The project proposal was developed in consultation with major sweet corn companies and their agronomists in QLD and WA. Project team members in each location have consulted with local growers and farm managers to understand their farm biosecurity and COVID-19 plans to facilitate property access and sampling. Growers’ local agronomists and farm managers are supporting the crop survey and sample collections.

The research aims of this project are to conduct a comprehensive literature review of FAW parasitoids, undertake an economic risk analysis for relevant horticultural crops in Australia, and conduct field surveys to study FAW host plants and its endemic parasitoids.

“Project staff are conducting regular field surveys and crop sampling to study the host crops and endemic parasitoid fauna associated with FAW. The team is collaboratively conducting a literature review, and collection of field data for crop risk analysis and extension activities,” Dr Subramaniam explained.

Data on host plants and crop losses caused by FAW are generated through crop surveys in production areas and discussions with technical experts, and is supplemented by international experience. The project team will calculate the risk that horticultural crops in Northern Australia face from FAW populations.

“The project team has developed a standardised sampling plan and protocols to conduct crop and parasitoid surveys on a national basis. This protocol has considered current farm biosecurity measures, work, health and safety procedures and COVID-19 mitigation measures,” Dr Subramaniam said.

Survey updates

The first field survey commenced in crops and weeds in the FAW-established locations such as Bowen and Burdekin in QLD, Darwin and Katherine in NT, and Kununurra and Broome in WA.

Highly preferred FAW host crops such as sweet corn, maize and sorghum have been targeted for collection of life stages of FAW and other Lepidopteran pests.

Fully grown fall armyworm larvae feeding inside fruit.

At the time of writing, autumn and winter field surveys had been completed in the QLD, WA and NT locations, targeting sweet corn, capsicum, melons and maize crops. Parasitoids and other beneficials reared from the field collections have been curated and sent to insect taxonomist Dr Erinn Fagan-Jeffries, who is based at the University of Adelaide, for identification and confirmation.

Five endemic parasitoid and three predator species that attack egg and larval stages of FAW were discovered by the team during the season.

“The project team has already progressed with the comprehensive literature review on FAW parasitoids that were reported in various countries where FAW has established several years ago. Also, crop surveys conducted in north QLD have identified and confirmed FAW infestation in capsicum crops and quantified the damage pattern in the fruit,” Dr Subramaniam said.

The team has also established contact and collaboration with several international scientists working in government agencies, universities and private companies in the United States, Switzerland, China, Africa and India.

“We have learnt more about FAW monitoring and biology, host crop range, insecticide resistance issues, potential biological control agents in various climatic conditions and new tools and technologies used in its management,” Dr Subramaniam added.

Industry benefits

The literature review will provide detailed information on FAW, and associated parasitoids (and other biocontrol agents) reported in Australia and overseas and will investigate the potential species that are suitable for tropical and sub-tropical production regions of Australia.

“Understanding the parasitoid and predatory fauna that are naturally occurring in the production regions will result in a positive economic impact for growers. This will allow growers and consultants to make better decisions on whether to spray crops or select ‘softer’ insecticides and measures to preserve the beneficial populations,” Dr Subramaniam said.

“Local information on FAW-established locations, host range, infestation levels and damage patterns will improve the adoption of pest management practices and result in a reduction in economic damage. Knowing the host plant range will enable growers to manage cultivated crops and surrounding non-crops (e.g., weeds and cover crops) to reduce FAW populations.”

MT19015: The bottom line

The long-term aims of this multi-industry project, led by Dr Siva Subramaniam, are:

  • To establish a list of endemic parasitoid species present in horticultural crops and recommendations of potential candidates for future biological control of fall armyworm (FAW).
  • Generate local information on FAW-established locations, host range, infestation levels on horticultural crops and damage patterns.
  • This information can then be utilised to develop an environmentally sustainable and long-term management strategy for vegetable crops.

MT19015 is complemented by another FAW project entitled Co-developing and extending integrated Spodoptera frugiperda (fall armyworm) management systems for the Australian vegetable industry (VG20003), which is a strategic levy investment under the Hort Innovation Vegetable Fund. This is also led by Dr Subramaniam from the Department of Agriculture and Fisheries, Queensland.

Outcomes from VG20003 will provide the foundation for a FAW Integrated Pest Management program and support further development of potential biological control agents for FAW management.

Find out more

Please contact Dr Siva Subramaniam at siva.subramaniam@daf.qld.gov.au.

This project has been funded by Hort Innovation using the melon, nursery, sweetpotato, turf and vegetable research and development levies and contributions from the Australian Government.

Project Number: MT19015

Cover image: Parasitoid attending fall armyworm eggs in sweet corn. Images courtesy of the Department of Agriculture and Fisheries, Queensland.