Identifying potential parasitoids of the fall armyworm, Spodoptera frugiperda, and the risk to Australian horticulture (MT19015)
What was it all about?
This investment, which ran from early 2021 to 2022, examined potential parasitoids of fall armyworm and delivered extension materials to growers on how to effectively manage the pest. The research team identified parasitoid species present in horticultural crops and provided recommendations on potential candidates for future biological control of fall armyworm, as well as local information on established locations, host range, infestation levels on horticultural crops and damage patterns.
Between March 2021 and May 2022, the project team conducted field surveys around Australia with a focus on sweet corn, capsicum and melon growing areas. The work investigated the potential use of predator insects (parasitoids) to manage the armyworm. More than 6,400 fall armyworm larvae and 750 egg masses were sampled across 65 locations and reared to recover parasitoid species.
The number of parasitised fall armyworm larvae varied between 1.3 and 47 per cent of larvae collected at different sites, with a total of 961 parasitised larvae recovered from across all locations.
The team discovered 18 endemic parasitoid species that attack egg and larval stages of fall armyworm. The species were taxonomically identified using molecular techniques and morphological characters. Among the list, three species are unique to Australia and have not been previously reported as attacking fall armyworm larvae. Better understanding of the parasitoid and predatory fauna will allow growers and consultants to make better decisions about spray timing and pesticide selection, including using ‘softer’ insecticides to preserve beneficial populations.
A literature review on predators associated with armyworm was also undertaken, which identified 87 species known to attack the armyworm, with 15 known species already in Australia. The next step is to investigate the potential of these for controlling armyworm nationally. The team also documented an armyworm host plant list to help growers manage cultivated crops and surrounding non-crop areas to reduce pest populations.
The project economist has calculated the risk that horticultural crops in Northern Australia face from fall armyworm populations. In the first-year, losses total $409 million or 23 per cent of total losses. However, once industry adjustment occurs, losses are dramatically reduced with an estimated annual loss of $59 million across Northern Australia.
Download the guide for Management of fall armyworm in vegetable crops in Australia (Nov 2021) from the AUSVEG website.
Read more in this article about Managing fall armyworm: a destructive, fast-moving pest, published in Vegetables Australia, Summer 2021/22 edition, pages 88 -89.
Watch this recording of a Fall Armyworm management research update presented by Siva Subramaniam on 30 September 2021 as part of DAF’s Vegetable Industry Webinar series hosted by Heidi Parkes.