Bemisia tabaci (Genn.): Biotypes and Cassava Mosaic Virus in India

Biology of Bemisia tabaci on five different host plants viz., cassava, sweet potato, cotton, egg plant and tobacco showed that developmental duration was maximum on cassava and fecundity was maximum on tobacco. Population of cassava whitefly (CWF) and sweet potato whitefly (SPWF) separately maintained on the respective host plants were used in two sets of experiments viz., choice and no-choice studies on cassava, sweet potato, egg plant, cotton, tobacco and tomato. Oviposition was recorded on all host plants, but no CWF nymphs emerged beyond the first instars on sweet potato, while there was no pupal formation or adult development of SPWF on cassava. In choice tests, CWF reproduced on cassava, egg plant, tomato and tobacco, but not on cotton and sweet potato. Conversely, SPWF reproduced on sweet potato, cotton, egg plant, tomato and tobacco, but not on cassava, indicating two different biotypes. In isozymes studies five non-shared alleles to CWF and six to SPWF were observed, ascertaining the biotypes. The analysis of amplification products obtained using the single primers revealed that the CWF and SPWF do not share any similarity among them, confirming the biotypes. Secondary endosymbionts were not associated with the two biotypes.