Rate of development and the survival of pupae ofDiabrotica virgifera virgiferaLeConte andD. undecimpunctata howardiBarber were studied under numerous constant temperature and humidity regimes. Temperature range for maximum survival, as measured by eclosion, was 18–30°C forD. v. virgiferaand 15–30°C forD. v. howardi.Time of development within these temperature ranges was similar for both species (5–10 days). At all temperatures studied, a saturated atmosphere (100% RH) was optimal for pupal survival and development.