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Label extension delivers sustainable RLEM control in canola

GRDC and cesar work with Syngenta to deliver label extension for PEGASUS®, for RLEM in canola.

Grain growers now have access to an additional tool for control of redlegged earth mite (RLEM) in canola crops.

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 a Grains Research and Development Corporation (GRDC) investment.PEGASUS, a Group 12A insecticide, is a Syngenta product with the active ingredient of diafenthiuron (see label at

GRDC Manager Pests, Leigh Nelson, said the label variation is welcome news for 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 is of real concern to the grains industry, so the registration of another insecticide option will 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 (IPM) program that includes cultural practices, seed treatments and rotation of insecticides with different modes of action.”

According to the label, PEGASUS can 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 in 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 are registered only for use as seed treatments.

“Resistance to pyrethroids and organophosphates in RLEM is widespread in Western Australia. These resistances have also been detected in some South Australian mite populations and are expected to be confirmed in other regions in future,” said cesar director, Dr Paul Umina.

“Having more chemical options for management is crucial to the longevity of chemical options for RLEM.” 

Syngenta’s Head of Portfolio ANZ, Peter Holmes, said working with the GRDC and cesar to extend the label for PEGASUS is part of 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. 

“The label extension of a popular product such as Pegasus® will enable growers to sustainably control RLEM and manage further pest resistance.”  

To assist 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 grain growing 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," Dr Umina said.