Temperature-dependent parasitism and development in Aenasius arizonensis Girault (Hymenoptera: Encyrtidae), a solitary endoparasitoid of Phenacoccus solenopsis (Hemiptera: Pseudococcidae)

Abstract

ABSTRACTOphmella communa (Coleoptera: Chrysomelidae) is a biological control agent of Ambrosia artemisiifolia (Asterales: Asteraceae). To reveal its climate adaptation, the effect of temperature on life traits of Aenasius arizonensis, a parasitoid of Phenacoccus solenopsis was studied. The results showed that both the highest parasitism and emergence rates of A. arizonensis were 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 of A. arizonensis is 31 °C in the insectary based on the results of our study.