What was it all about?

From 2015 to 2019, this investment completed the second phase of research into the use of the Mastrus ridens wasp as a biocontrol agent against codling moth in apples. Specifically, this phase involved release of the wasp into sites in southern Queensland, New South Wales, South Australia, Tasmania and Victoria for study of the wasp’s dispersal, predation and hyper-parasitism. Project activities included rearing the wasp (Mastrus ridens) and host (codling moth), pesticide testing, field releases of the wasp, establishment detection and monitoring, efficacy assessments, and communication and awareness activities.

Codling moth is the key apple and pear tree pest in all Australian growing regions except Western Australia. The Australian industry has for many years invested in research to reduce reliance on synthetic pesticides, adopting biological control options and agronomic practices to provide economically and environmentally sustainable pest, disease and crop management.

From 2016-2019 approximately 50,000 of the wasps were released in a staged approach:

• 2016 – two Queensland orchards
• 2017 – five orchards in NSW and one in Tasmania
• 2018 – two orchards in South Australia plus two in Victoria
• 2019 – one NSW orchard.

Adult wasps were evident at all sites for a week after release. In the season following, codling moth populations crashed at the sites measured, with greatly reduced levels of damage.

The research team also investigated the direct and indirect effects of common pesticides on Mastrus ridens, with some having effect on adult wasps, whilst others influenced fertility and performance of subsequent generation. This is being shared with industry to help inform spay planning.

The project team have confirmed the potential of the parasitoid to enhance the management of codling moth in Australia

Guidelines for production of the wasp and its host codling moth have been developed so that commercial producers of biocontrol agents can assess feasibility of incorporating Mastrus ridens into their suite of products.

Information about the project and its results have been widely shared across the industry, including articles in relevant industry publications, presentations at seminars and conferences, attendance at field days, and the provision of training sessions and workshops.

ACT NOW

Learn more about the project on the team’s ExtensionAus website, including a video showing the Mastrus ridens wasp in action.

Read more about the research and project outcomes in these articles:

• Orchard plant protection guide for deciduous fruits in NSW 2018-19, page 11, published by NSW DPI
• Subscribe or log in to access New methods to target codling moth in the Oct/Nov 2018 edition of the Australian Tree Crop, pages 12-13
• A new biocontrol agent and mass-trapping of codling moth published in Tree Fruit magazine, 2018
• Killer wasps and better pheromones target codling moth from 2018 in Australian Fruitgrower edition 12(3) on pages 26-27
• Advances in codling moth control in orchards from 2016 in Australian Fruitgrower edition, republished on the APAL extension website.