Russian Wheat Aphid: a Growing Problem for Small-Grain Farmers

Abstract

The Russian wheat aphid (RWA), Diuraphis noxia. has only recently become a serious pest of wheat and barley. Its effects are being felt in many parts of the world. Originally recorded in 1900 in the southern Soviet Union, it has spread to Africa and America and is now considered a threat to the Australian wheat industry. In terms of crop loss and management, RWA has cost the small-grain farmers of the western USA over $300 million since its appearance in 1986. RWA feeds deep within the leaf whorl inside tightly rolled leaves, and is consequently difficult to control with insecticides. During feeding, the aphid injects a toxin into the plant which appears to destroy the chloroplast membrane. Predators and parasitoids find it difficult to locate the aphid. Host-plant resistance represents a practical management option.