Ophmella communa(Coleoptera: Chrysomelidae) is a biological control agent ofAmbrosia artemisiifolia(Asterales: Asteraceae). To reveal its climate adaptation, the effect of temperature on life traits ofAenasius arizonensis, a parasitoid ofPhenacoccus solenopsiswas studied. The results showed that both the highest parasitism and emergence rates ofA. arizonensiswere observed at 31 °C. The parasitism and emergence rates of the parasitoid significantly increased with the increasing temperature from 19 °C to 31 °C, but dropped when the temperature exceeded 31 °C. Female ratio reached a higher value at 19, 22, 31, 34 or 37 °C. The minimum threshold temperatures for female and male parasitoids were 11.5 and 11.2 °C, respectively. The effective accumulative temperatures for the parasitoid to develop from eggs to both female and male adults were 222.2 day-degrees. Since the highest parasitism rate, the highest emergence rate and a higher female ratio were observed at 31 °C, we conclude that the optimum temperature for mass rearing ofA. arizonensisis 31 °C in the insectary based on the results of our study. [ABSTRACT FROM PUBLISHER]