Incidence and species composition of aphids infesting wheat.
The wheat crop under Delhi conditions was found mainly infested with two species, Indian grain aphid, Macrosiphum miscanthi Takahashi, and bird cherry oat aphid, Rhopalosiphum padi (Linnaeus). A low infestation of another species, the corn leaf aphid, Rhopalosiphum maidis (Fitch) was also noticed during 1998-99. The three species had a distinct preference for their site of infestation. R. padi infested all above ground plant parts, but was more preponderant on leaves and stem (foliage). M. miscanthi infested leaves and earheads, but was the dominant species on earheads. R. maidis incidence was confined to leaf whorls only.