MANAGING arthropod pests in cropping systems relies on good biological and cultural practices backed-up with carefully selected and well-timed pesticide applications.
While some information about the impact of pesticides on beneficial arthropods exists both in Australia and overseas, there are gaps in the available knowledge and the results need to be regularly updated as new chemicals become available.
Identifying and filling these knowledge gaps is the focus of current research by horticultural entomologists.
A team of entomologists led by Jessica Page (IPM Technologies) and in collaboration with Maarten Van Helden (South Australian Research and Development Institute) and Lara Senior and Zara Hall (Queensland Department of Agriculture and Fisheries), is working towards identifying the impact of integrated pest management (IPM) compatible products on beneficial insects that are important in Australian vegetable crops.
In laboratory trials, scientists are exposing beneficial insects to pesticide residues and recording the impact on their survival.
The scientists are also testing the impact pesticides have on non-lethal development such as egg lay and survival of offspring.
Follow up checks are being conducted on some chemicals that have shown elevated toxicity through trials on treated whole plants to simulate a more 'real life' situation as opposed to the 'worst case scenario' from laboratory testing.
Results to date have been interesting and sometimes surprising: Several predator species show high adult mortality compared to juvenile stages which contradicts previously held beliefs that juvenile stages are the most vulnerable to the impacts of pesticides.
There have also been differences in the toxicity of some products to different beneficial species which means that for a product to be considered "safe" or "not safe" will depend on which beneficial species a grower is wanting to protect.
Testing is ongoing and will be made available to industry in a series of guides once checks have been completed.
The aim of the guides is to provide useable information to vegetable growers and advisors about how to choose the right pesticides to support biological control in IPM programs.
This research forms part of project VG16067, funded by Hort Innovation using the vegetable industry levy and matched funds from the Australian Government and IPM Technologies.
If you would like further information about this research, please contact the project lead, Jessica Page, IPM Technologies, at email@example.com
- Zara Hall is a horticulturist with the Department of Agriculture and Fisheries