This book describes number of aphid species attacking wheat varieties, population dynamics of aphid's species by collecting them from the field by using different collection techniques, and examine them in the laboratory under the microscope for the sake of species identification. The effect of abiotic factors on aphid's population was also determined. Four species of wheat aphid viz., Schizaphis graminum, Sitobion avenae, Rhopalosiphum padi and Rhopalosiphum maidis were identified on the basis of their taxonomic characters out of which S. graminum was most destructive. SARC-2 and SARC-8 were found to be most susceptible and most resistant, respectively. Peak population of aphids was observed in middle period of March. Abiotic factors showed significant role in population fluctuation of aphids.