Abstract

The life history and life table of Bemisia tabaci Gennadius on cucumber was studied under laboratory conditions at 20, 25 and 30°C. The overall developmental time varied from 34.8 days at 20°C to 14.1 days at 30°C. Immature mortality decreased from 45.8 to 17.3% with increasing temperature. The threshold temperatures of egg, 1st, 2nd, 3rd and 4th nymphal stage and a generation were 14.72, 14.36, 10.18, 11.40, 14.36 and 13.07°C whereas the degree-day requirement at each stage was 64.44, 42.39, 49.19, 33.19, 35.46 and 229.52 DD, respectively. Female longevity ranged from 16.8-34.1 days. Mean total fecundity ranged from 150-263 eggs/female. Mean daily fecundity ranged from 4.2-12.7 eggs/female, increasing with increasing temperature. Values for rm varied from 0.066 to 0.191 being least at 20°C and greatest at 30°C. Generation times decreased from 43 to 19 days with increasing temperature. The results indicate that B. tabaci is well adapted to high temperatures and may extend its distribution if mean world temperatures increase as a result of global warming.