Influence of Plant Growth Stage on Cereal Aphid Reproduction

Abstract

The objective of this research was to determine the influence of the stage of growth of host plants upon the fecundity of cereal aphids. This information is useful in evaluating the potential for cereal aphid movement between, and their colonization of, a sequence of field crops in the Northern Plains and in understanding the epidemiology of plant virus diseases transmitted by cereal aphids. Aphid fecundity was tested in growth chambers on spring wheat (Triticum aestivum L.), spring barley (Hordeum vulgare L.), sorghum [Sorghum bicolor (L.) Moench], and maize (Zea mays L.) when plants were in the seedling (2—3 leaf), boot, heading, and flowering stages of growth. Aphid fecundity was also compared on vernalized and nonvernalized winter wheat. The aphids tested were the greenbug (GB) [Schizaphis graminum (Rondani)], the English grain aphid (EGA) [Macrosiphum (Sitobion) avenae (F.)], the bird‐cherry oat aphid (RP) [Rhopalosiphum padi (L.)], and the corn leaf aphid (CLA) [R. maidis (Fitch)]. The results of the tests showed that GB and RP reproduced more on headed wheat than on earlier stages of wheat growth. CLA fecundity was significantly greater on seedling barley than on later stages of growth, but there were no significant differences in GB, RP, and EGA reproduction on barley at the several stages of growth. Seedling maize was virtually immune to RP and CLA colonization; however, GB, RP, and CLA reproduction was greater on seedling sorghum than on older plants. No significant differences were detected in the fecundity of GB, RP, or EGA on vernalized versus nonvernalized winter wheat. The results are interpreted in the context of cereal aphid field biology and stage of crop development in the Northern Plains.