Parasitism of the castor whitefly, Trialeurodes ricini (Homoptera: Aleyrodidae) by Encarsia formosa (Hymenoptera: Aphelinidae): bionomics in relation to temperature.
Selected life history characteristics of the biological control agent Encarsia formosa parasitizing the castor whitefly, Trialeurodes ricini, were studied at three constant temperatures (20, 25 and 30°C). Egg-to-adult developmental time decreased from 32 days at 20°C to 13 days at 30°C. An average of 241 day-degrees was required to complete development above the lower threshold temperature (12°C). Juvenile mortality was 34, 40 and 47% at 20, 25 and 30°C, respectively. Mean longevity of E. formosa ranged from 7.7 days at 20°C, to 2.6 days at 30°C. Mean total fecundity ranged from 18 to 36 eggs/female. Intrinsic rate of increase (rm) increased with temperature from 0.065/day at 20°C to 0.169/day at 30°C. Generation times decreased from 37 to 14.5 days with increasing temperatures.