Russian wheat aphid

Russian wheat aphid (Diuraphis noxia; RWA) was first identified in South Australia in 2016. This cereal pest is now present in cropping areas of SA, Victoria, Tasmania, New South Wales and Western Australia.

image of RWA. Photo Tom Heddle PIRSA-SARDI-resize-620
Monitoring and making threshold-based decisions are key to effective long-term management of Russian wheat aphid. Photo Tom Heddle PIRSA-SARDI.

Research

We’ve achieved a growing knowledge base about RWA through our research investments. This is continually providing the Australian grains industry with a greater understanding of the pest and its potential impact, to inform management strategies.

In addition to experiments to determine aphid biotype (there is a single biotype in Australia), we’ve been investing in:

  • research to determine the level of susceptibility or resistance of commercial wheat and barley cultivars to RWA
  • RWA biology, ecology and economic thresholds under Australian conditions
  • an investigation into alternate hosts for RWA
  • trials looking at insecticide efficacy
  • development of a green bridge risk forecasting tool
  • assessing potential sources of plant resistance
  • provision of practical resources for growers and advisers.

Important resources and knowledge generated from our research investments – including an action threshold calculator – are available via the provided links.

Migration and management

For most grain growing regions (Tasmania has been observed to be a frequent exception), RWA populations are expected to grow within cultivated crops over the winter. They will then disperse during a spring migration into refuges to ‘over-summer’, and then re-disperse back into emerging crops during an autumn migration.

Yield impact requires aphids to migrate into emerging crops at an early growth stage (during crop establishment) and to build to high numbers leading up to head emergence.

Together with the broader grains industry, we will continue to promote the FITE (find, identify, threshold approach and enact) strategy which was developed to provide growers and advisers with a simple guide to RWA management.

It involves:

  • Find – look for aphids and the characteristic plant symptoms of infection including leaf streaking or leaf rolling on cereal crops and grasses
  • Identify – positively identify RWA by consulting with an industry specialist
  • Threshold approach – before deciding on your plan of attack consider thresholds for control, the presence of natural aphid enemies in the crop, crop growth stage and potential yield losses
  • Enact – take appropriate action: manage your next steps including encouraging beneficial insects and protecting honeybees before implementing control options.

Resources

image of monitoring & decision points

Important considerations when using action threshold advice for RWA.

Tools

Action threshold calculator

Action threshold calculator instructions

Videos

Podcasts

Publications

Websites