Russian wheat aphid (Diuraphis noxia) (RWA) is a new pest that was first found in South Australia in May 2016. By mid-2017 infestation had spread to Tasmania, Victoria and New South Wales (NSW Department of Primary Industries, 2017). The warmer, drier climates of Australia’s cropping zones provide a perfect climate for the pest to reproduce and thrive. It is now unfeasible to eradicate the RWA from Australia, therefore growers must manage the pest in order to minimise its damage to crops and its spread to new areas.
While the Russian wheat aphid is a new pest growers must watch out for, it can be managed through a range of cultural, chemical and biological control methods. Like other pests, practicing rotational cropping to break the life cycle of the insect will help minimise infection and damage to crops. Ensuring there is no “green bridge” from volunteer cereals before sowing is a vital management step to ensure there is no RWA present in the paddock prior to sowing. Preliminary research has shown that seed treatments can provide early protection against RWA (Umina, Baker, & Edwards , 2017). This is particularly useful when crops are being sown in high risk situations such as early sown crops or paddocks with volunteer cereals. A number of natural enemies of the RWA are present in cropping areas. These include parasitic wasps, ladybird beetles, lacewings, damsel bugs and hoverflies. There are now a number of registered chemicals available for the control of RWA. The threshold for RWA management with a chemical control is warranted when more than 20% of seedlings are infested before tillering and 10% of tillers infested after tillering (Umina, Baker, & Edwards , 2017).
While the RWA is a new pest to Australia which poses a threat to wheat and barley crops, a sound integrated pest management strategy will minimise crop damage. Research into the pest will continue in order to gain a better understanding of the life cycle and future control methods.
For more information on the Russian Wheat Aphid please follow the below links to industry publications: https://grdc.com.au/__data/assets/pdf_file/0027/244377/Russian-Wheat-Aphid-Tactics-for-Future-Control.PDF