Rhopalosiphum rufiabdominale

The rice root aphid or red rice root aphid (Rhopalosiphum rufiabdominale) is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is found in rice and many other plants.

Hosts

The rice root aphid has a broad host range, having been found on many species of plant distributed across 22 plant families.^[3][4] It is a palearctic species which has probably originated in eastern Asia.^[5] It is principally a pest of upland rice but not of lowland, irrigated rice. Other crops affected include oats, barley, millet and wheat, eggplant, marrow, cotton, tobacco, potato, tomato and sugarcane. Its incidence in cereal crops may be under-reported because it may pass unnoticed because of its underground habits. It has been recorded as undergoing its complete life cycle on plum (Prunus domestica) and apricot (Prunus armeniaca) in Italy and has become a pest of hydroponic systems in greenhouse cultivation in various parts of the world.^[6] The plum (Prunus) is probably its primary host.^[5]

Damage

The species feeds on the roots and stems of rice plants. In severe infestations of the roots, the plants die, while in lesser ones, the plants wilt, and become discoloured and distorted, with the formation of rosettes.^[6]

This aphid is a vector of cereal yellow dwarf virus and barley yellow dwarf virus, and this makes it a pest of economic importance in barley cropping in North America and Turkey. In India it is thought to transmit maize mosaic virus and sugarcane mosaic virus.^[6]

Prevention and control

Systemic insecticides are used against this pest, but are largely ineffective in rice crops. Soil treatment can also be used, but this has the disadvantage of killing ants. In greenhouse crops of squash in Florida, the entomopathogenic fungus Lecanicillium lecanii has controlled this aphid. Parasitic wasps in the genus Aphelinus are believed to be parasitoids of this aphid in upland rice in China, but little is otherwise known of the natural enemies of this species. In India, seed potato crops grown at altitudes above about 2,000 m (6,600 ft) are largely uncolonised by this aphid.^[6]

References