Bemisia tabaci (Gennadius) adults from colonies reared on cassava or sweet potato plants were studied to determine their ability to transmit Indian cassava mosaic virus (ICMV) (Geminiviridae: Begomovirus) from cassava to cassava. Virus acquisition access (feeding) periods (AAP) of 48 h on ICMV-infected cassava leaves and 48-h virus inoculation access (feeding) periods on virus-free cassava seedling leaves were investigated. ICMV was successfully transmitted from cassava to cassava by whiteflies reared on cassava, but not whiteflies reared on sweet potato. Virus-specific primers were designed around conserved regions of the coat protein gene (CP) (771 bases) of the Trivandrum (Tri; GenBank accession number AF423180) isolate and used for virus detection in the whitefly vector after different AAP. The activities of the cyanide detoxifying enzymes rhodanese and β-cyanoalanine synthase in B. tabaci were evaluated and shown to be significantly higher in the cassava-reared whitefly population compared with the sweet potato-reared population suggesting a possible reason for higher mortality of the sweet potato strain feeding on cassava. Mating compatibility studies between cassava and sweet potato colony whiteflies resulted in production of fertile offspring with no evidence for reproductive isolation. Results confirm that only B. tabaci whiteflies reared on cassava transmit ICMV from cassava to cassava in India.