Entomology Professor Frank Peairs from the Department of Bioagricultural Sciences and Pest Management at Colorado State University in the US, will speak at a Grains Research and Development Corporation (GRDC) Grains Research Update in Wagga  on February 14 and 15.

The aphids were found in southern NSW recently, after first being detected in Australia on a South Australian property last May. They have also now been confirmed in Victoria’s grain growing regions.

Dr Peairs has extension, research and teaching responsibilities in the management of arthropod pests of Colorado field crops. For many years his focus has been the biology and management of RWA and he has published more than 100 peer reviewed journal articles on the crop pest.

“Unfortunately RWA has been expanding its range since the 1970s and has spread to every major wheat producing region in the world,” he said.

“Since its arrival in my home state of Colorado in 1986, it has caused losses of more than US $200 million, but biological control measures have essentially reduced its status, and our last major outbreak was in 2009.

“Crop diversification, modified planting dates and promoting general crop health and vigor are considered important cultural management practices in defeating the aphids.”

Dr Peairs says in addition, long term efficacy data supports the use of chlorpyrifos to control RWA, however, the newer lambda cyhalothrin + thiamethoxam mixtures are equally effective.

“Neonicotinoid seed treatments are effective in our spring grains, but don’t provide season-long protection in winter wheat.

“We released 10 winter wheat varieties resistant to the original RWA biotype, however they have all proven susceptible to the currently dominant biotype, so our management now relies on cultural practices and naturally occurring biological controls supported by chlorpyrifos treatments based on scouting.”