A population ofClitostethus arcuatus(Rossi), originating in Israel, was imported into California in 1989. Laboratory studies at three temperatures (21.1, 28.2, 32.2°C) usingSiphoninus phillyreae(Haliday) as prey indicated maximum developmental rates, survival, and fertility at 28.2°C. At 28.2°C, development from egg to adult required a mean of 15.6 d, egg-to-adult survival was 78%, sex ratio of surviving progeny was 1:1, females lived an average of 82 d and laid an average of 202 eggs. Developmental rates and fertility were slightly lower and survival was similar at 21.1°C. Development was slower and survival and fertility were reduced substantially at 32.2°C.