Savopoulou-Soultani, M. 1997 Laboratory rearing of euonymus scale (Homoptera, Diaspididae) at different temperatures.. Journal of Economic Entomology 90: 955-960.

Notes: Developmental rate (stage specific and total), survival, fecundity, and sex ratio of Unaspis euonymi (Comstock) were studied in environmental chambers maintained at 6 constant temperatures of 5, 10, 15, 20, 25, and 30 degree C. Scales were reared in the laboratory on discs cut from Euonymus japonica L. (Celastraceae) leaves floated on distilled water in plastic cups. Optimal temperature for development, survival, and reproduction, was 25 degree C. Survival was low at the lower and higher extremities of temperature for 1st instars for either males or females. A good linear model fit between developmental rate and temperature was obtained for almost all U. euonymi stages. The lower developmental threshold was 5.7 degree C for 2nd-instar females and ranged from 5.7 degree C (2nd-instar females) to 15.4 degree C (pupae of males). Degree-days required by U. euonymi males to complete the 2 larval stadia and pupal stage were 181.8, 109.1, and 361, respectively. Females completed their 2 larval stadia in 178.9 and 299.4 DD. Finally, 473.9 and 458.7 DD were required for the total development (from 1st instar to adult stage) of males and females, respectively. Sex ratio was apprxeq 1:1 at all temperatures tested (15, 20, and 25 degree C).