author(s)
R Tamilselvan, CA Mahalingam, S Mohan Kumar and K Senguttuvan

abstract
Biology of whitefly, Bemisia tabaci was studied on resistant (LHDP-1 and Supriya), moderately resistant (CCH-4474 and GJHV-517) and susceptible (TCH-1819 and Bunny) cotton genotypes under screen house condition. The data on the biology (incubation period, nymphal period, total developmental period, oviposition period, fecundity and sex ratio) were conducted. All the genotypes showed significant differences against whitefly biology. The genotype Bunny was observed to be more preferred for egg laying (59.25 eggs/two pairs) followed by TCH-1819, while other genotypes were less susceptible for egg laying. Longest incubation period was found on the genotype Supriya (6.00 days) and shortest was on GJHV-517 (5.50 days). Oviposition period, longevity and sex ratio was observed to be higher in the genotype TCH-1819 when compared to other genotypes. Total developmental period (20.42 days) and pre-oviposition period (2.50 days) was found to be maximum in Supriya, while it was minimum in all other genotypes.