Russian wheat aphid has a great economic impact on cereal crops. Although it causes damage to the leaves and flowers of wheat and barley when feeding on them, its main impact is caused by a toxin it injects into the plant. This leads to yellowing of the plant, stunted growth and loss of vigour. It is also a minor pest of oats, rye, sorghum and triticale and can spread barley yellow dwarf virus, brome mosaic virus and barley stripe mosaic virus. The Russian wheat aphid’s host range also includes several non-crop grass species that occur in Australia.
There are two life cycle forms of the Russian wheat aphid: the holocyclic form which refers to sexual reproduction and allows the aphid to hibernate as eggs, and the anholocyclic form which refers to a life cycle based on asexual reproduction. Anholocyclic forms produce adults that overwinter and must continue feeding during winter. All invasive populations of Russian wheat aphid outside its natural range have an anholocyclic life cycle and are parthenogenetic (reproduce without needing to mate). As a result, in most countries the aphid individuals are genetically identical.
The grains industry is the largest plant industry in Australia and grain crops are grown in all states and territories. Wheat and barley are the most important cultivated hosts of the aphid and can provide suitable habitat for the aphid for most of the year.
See if you can identify the pest
Everyone needs to keep an eye out for Russian wheat aphid.
Russian wheat aphid may occur on contaminated plant material, on machinery and other equipment. Adults and nymphs do not survive long without access to living plants. As a result, eggs are a more likely way for the aphid to enter Australia. In addition to human assisted spread, dispersal of winged adults can occur over large distances by wind-assisted flight.
This aphid is yellow-green to grey-green, spindle-shaped and about 2mm long as an adult. Although its surface is smooth just after moulting, it soon becomes covered with a waxy white exudate. It has a double tail at the tip of the abdomen, a feature that distinguishes it from all other cereal aphid species.
This aphid causes characteristic damage: white to purple streaking and leaf-rolling on wheat and barley leaves. Large colonies of aphids can roll the flag leaf to the point where the tip of the wheat head becomes trapped, giving it a fish-hook shape.
If you work around imported goods you need to look for Russian wheat aphid on:
- plant material including cut flowers
- shipping containers.
Many types of aphids are present in Australia, however no other cereal aphid has the characteristic double tail. Colonies are found most frequently on the youngest leaves or on newly emerged flowers/seed heads. Rolling ranges in severity from simple folding of the leaf along the mid-vein, to one side of the leaf rolled in upon itself, to the whole leaf being tightly rolled around the aphid colony.
Young plants are often stunted and even killed. Plants attacked after flowering show few or no obvious symptoms.
Grain growers are advised by the Russian Wheat Aphid National Technical Group to monitor their crops for infestations of the newly introduced Russian wheat aphid and to report suspected infestations but to hold off spraying wherever possible until spring.
Protect your farm from biosecurity risks, practice good on-farm biosecurity and regularly monitor your crops. Find out more about Russian wheat aphid management.
Check what can legally come into Australia
All Australians and international tourists have a role to keep out exotic pests and diseases.
Check what you can and cannot bring into Australia, whether you are a:
Keep unwanted aphids away!
The Russian wheat aphid is widespread in grain growing regions of the world. Australia remains free of the holocyclic form which produces males and females. It is important to prevent this form from establishing in Australia, as it will allow the aphid to overwinter as eggs.
Import restrictions and biosecurity measures
Some items, by law, are subject to certain import conditions to be allowed into Australia. Please check the
Biosecurity Import Condition System (BICON).
Be aware of any Russian wheat aphid biosecurity measures that may be in place for incoming goods and conveyances.
Industry advice notices are reviewed regularly and could change.
Secure any suspect specimens
Containment is critical. This could be as easy as bagging a suspect plant specimen that has symptoms or stopping an insect escaping by closing the doors on a shipping container.
Report detections of exotic pests
Any detections of Russian wheat aphid must be reported to the authorities.
If you receive or work around goods imported from overseas, including mail, you need to be vigilant to Russian wheat aphid and other exotic pests.
If you see an unusual pest, secure the goods to limit the movement of the pest and immediately report it to the Department of Agriculture and Water Resources
SEE. SECURE. REPORT. Hotline 1800 798 636 or by using the
Growers and home gardeners
If you see the Russian wheat aphid or anything unusual, report it to the
Exotic Plant Pest Hotline
1800 084 881. This will put you in touch with the Department of Primary Industries or agriculture in your state or territory.
When reporting your concern, you will be given advice on handling the specimen and what to do next until an officer can investigate.