The Pegasus miticide/insecticide label has been varied to include control of RLEM, Halotydeus destructor, in canola.
This registration was supported by research conducted by sustainable agriculture research organisation cesar through an investment from the GRDC.
Pegasus, a Group 12A insecticide, is a Syngenta product with the active ingredient of diafenthiuron.
GRDC manager - pests Leigh Nelson says news of the label variation will be welcomed by the nation's canola growers.
"RLEM is a major threat to a variety of Australian crops and pastures, and canola seedlings are among the most susceptible to attack," Dr Nelson said.
"Feeding on canola seedlings by mites can cause distortion and shrivelling of leaves, and when infestation is at a significant level, affected seedlings may die."
Dr Nelson said increasing RLEM resistance to commonly-used chemistries was a significant concern for the Australian grains industry, so the registration of an additional insecticide option would assist in extending the longevity of available chemical controls.
"It's another tool in the toolbox for our growers," Dr Nelson said.
"But as is the case with the use of any available chemistries, for best results Pegasus should be used as part of an integrated pest management program that includes cultural practices, seed treatments and rotation of insecticides with different modes of action."
According to the label, Pegasus is able to be applied to canola from the cotyledon stage when action thresholds are reached.
Growers are advised that thorough coverage is essential, and that they should not apply more than two applications to any one crop.
Four other chemical groups are registered to control RLEM in grain crops - organophosphates (Group 1B); synthetic pyrethroids (Group 3A); phenylpyrazoles (Group 2B); and neonicotinoids (Group 4A).
The latter two groups are registered only for use as seed treatments.
Syngenta head of portfolio ANZ Peter Holmes says working with the GRDC and cesar to extend the label for Pegasus matched well with Syngenta's innovation model to deliver solutions for more sustainable agriculture.
"It takes 11 years of research and development and millions of dollars to bring a new crop protection product to market, which is why it is so important that existing products are used safely and sustainably," Mr Holmes said.
To support growers with their efforts to control RLEM and address insecticide resistance, the GRDC, in conjunction with the National Insecticide Resistance Management working group, has recently updated the RLEM Resistance Management Strategy and expanded it to include all graingrowing regions.
This important document can be found on the GRDC website, as well as the IPM Guidelines for Grains website.
"I encourage growers and advisers to download this document and become familiar with the management options available and insecticide rotations recommended for RLEM," cesar director Paul Umina said.
Dr Umina's colleague at cesar, James Maino, warned that overuse of insecticide could lead to the evolution of resistance through selection pressure and highlighted that graingrowers needed to use the new product mindfully.
"RLEM has developed insecticide resistance previously, with resistance to synthetic pyrethroid and organophosphate chemicals being recorded for Western Australian populations," Dr Maino said.
More recently, cesar has identified several South Australian mite populations with extremely high resistance to pyrethroid chemicals, including bifenthrin and alpha-cypermethrin, as well as moderate resistance to organophosphates, including chlorpyrifos and omethoate.
"The spread of resistance can be slowed if techniques described in the resistance management strategy for RLEM are applied,'' Dr Maino said.
- Details: View the Redlegged Earth Mite Resistance Management Strategy at grdc.com.au