Russian wheat aphid (Diuraphis noxia) is an insect pest of global significance that was detected in Australia for the first time during 2016 in South Australia, Victoria and New South Wales. Western Australian grain growers are urged to monitor cereal crops for signs of this exotic pest which has potential to result in greater yield losses than other aphid species. If you think you may have found Russian wheat aphid in WA, please contact the Department of Agriculture and Food, Western Australia.
Diagnosing Russian wheat aphid
What to look for
- Russian wheat aphid is a small lime-green aphid with an elongated body. Adults are 1.4-2.3mm in length, the antennae are short, as are the cone shaped siphunculi (sometimes called cornicles). Supracaudal process is present, giving the appearance of a double tail. In South Australia during 2016, it was observed that Russian wheat aphid was often found as a low percentage of mixed colonies with other cereal aphid species (that is, 5% Russian wheat aphid, 95% corn aphid).
- Aphid damage is often found at the base and sheath of newly emerged leaves. Cereal crops infested with Russian wheat aphid can become purplish and develop longitudinal yellowish and whitish streaks. Infested plants may be stunted and damaged areas may appear in hotspots or along field edges. Tillers of heavily infested plants can run parallel to the ground and leaves can roll longitudinally. Curling of the flag leaf can cause merging heads and awns to become trapped. From a distance, damage may appear as a general loss of colouration across the affected crop area.
What else could it be
|Diagnosing cereal aphids||Aphid present on cereal crops||Russian wheat aphid are small in size, green in colour, elongate in shape with very short antennae and an apparent lack of cornicles (exhaust pipes)|
|Diagnosing wheat streak mosaic virus||Longitudinal striping of leaves sometimes present||Absence of aphids near the base of newly emerged leaves|
|Diagnosing group B herbicide damage in cereals||Changes in leaf colouration including yellow or white stripes and sometimes purpling||Absence of aphids near the base of newly emerged leaves|
Damage from thrips or mites
Where does it occur?
- Russian wheat aphid can occur on a range of cereal crops and grass weeds including wheat, barley, oats, rye and triticale. Wheat and barley are the most sensitive crops to damage from Russian wheat aphid. Oats are considered susceptible to at least one biotype of russian wheat aphid, but are resistant to most.
Where did it come from?
- Russian wheat aphid is an insect pest of global significance that was detected in Australia for the first time during 2016. Whilst it has not yet been found in Western Australia, grain growers are urged to remain vigilant. Conditions favourable to larger infestations are likely to be similar to other aphid species. These include an early break to the growinbg season and the presence of volunteer cereals during the period leading up to seeding.
Green bridge control
- If you think you may have found Russian wheat aphid in Western Australia please contact the Department of Agriculture and Food, Western Australia immediately.
Where to go for expert help
Page last updated: Wednesday, 22 March 2017 - 9:39am