none Development of Cardiochiles nigriceps Viereck in Heliothis virescens (F.) was determined at constant and fluctuating temperatures. The duration of the egg-larval stage varied from 45 days at 17 degree C to 9.3 days at 32.5 degree C. At temperatures below 22.5 degree C, the insects remained in diapause. The duration of the prepupal-pupal stage varied from 23.0 days at 22.5 degree C to 12.2 days at 32.5 degree C. Longevity of both sexes was similar and varied from 28 days at 20 degree C to 7.4 days at 35 degree C. The number of larvae parasitized per female per day increased from 0.44 per day at 20 degree C to 2.71 per day at 30 degree C.