Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Infraclass: Neoptera
Subclass: Pterygota
Order: Hemiptera
Suborder: Sternorrhyncha
Superfamily: Aphidoidea
Family: Aphididae
Subfamily: Aphidinae
Tribe: Macrosiphini
Genus: Diuraphis
Subject: Diuraphis noxia (Kurdjumov, 1913)

The Russian wheat aphid is native to southwestern parts of Asia. It was introduced to many countries in Europe and Africa. It was first found in the U.S. in 1986 in Texas. The species was probably transmitted through wheat imports.

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In its native range the life history of RWA includes sexual and asexual phases. However, like most other introduced aphid pests in Australia, invasive populations of RWA reproduce asexually with females giving birth to live female offspring.
In autumn, aphids may infest wheat seedlings soon after emergence, usually from wingless aphids walking off nearby senescing hosts. Russian wheat aphid requires actively growing plants for development. Population growth begins from tillering and stem elongation and becomes most rapid from booting onwards. Early in the crop cycle, the vast majority of aphids are wingless. Later in the crop cycle as aphid population density increases, the proportion of winged aphids increases and may reach high levels prior to ripening. At this stage, aphids emigrate in search of alternative summer hosts.
Russian wheat aphid is able to survive under a wide range of temperatures and may perform better at lower temperatures than other cereal aphid pests. However, higher temperatures (>25°C) may limit the distribution of RWA. Under laboratory conditions, generation time ranges from approx. 20 days at 10°C, and 9 days at 20°C.

Damage is restricted to specific members of the grass family. Wheat and barley are the most susceptible; rye and triticale, while susceptible, are usually less damaged; and oats appear to sustain little or no injury. Russian wheat aphid does not attack corn, sorghum, or rice. While feeding, Russian wheat aphid injects a toxin into the plant. This toxin is responsible for many of the damage symptoms, the most characteristic of which are white, longitudinal streaks on the leaves and sometimes the stem. Heavily infested plants are stunted, and sometimes exhibit a flattened appearance with tillers lying almost parallel to the ground. Occasionally, particularly during cold weather, plants show a purple color. Infested leaves curl up like a soda straw and remain in a rigid upright position rather than assuming the typical drooping posture. The tightly curled, upright leaves resemble onion leaves. If the awns are trapped in the curled flag leaf, the head is usually distorted and assumes a fish hook appearance. Improperly timed applications of phenoxy herbicides may cause similar injury.
Russian wheat aphid is not a vector of barley yellow dwarf virus.

Like other aphids, the nymphs and adults suck the sap from plants, particularly from their ears. They appear on young leaves or ears in large numbers during the cold and cloudy weather. The damage is particularly severe in years of cold and cloudy weather. A heavily manured, well-irrigated and succulent crop will harbour the pest for a longer period and suffer greater damage.

Potassium phosphate was studied as a resistance inducer on wheat plants against D. noxia. It may serve as a method to deal with the population of aphids that have overcome wheat’s genetic resistance. The study indicated that potassium phosphate treated plants either a resistant strain or a non-resistant strain both show a decrease in aphid numbers that were feeding. Thus the data suggests treating wheat with potassium phosphate to induce tolerance against D. noxia.

Potassium phosphate was studied as a resistance inducer on wheat plants against D. noxia. It may serve as a method to deal with the population of aphids that have overcome wheat’s genetic resistance. The study indicated that potassium phosphate treated plants either a resistant strain or a non-resistant strain both show a decrease in aphid numbers that were feeding. Thus the data suggests treating wheat with potassium phosphate to induce tolerance against D. noxia.