Li, C.Y., & Tsong, H.S. 2002 Effects of temperature on development of the hemispherical scale, Saissetia coffeae (Walker) (Homoptera: Coccidae), and its occurrence on cycad (Cycas taiwanian Carr.).. Formosan Entomologist 22(1): 65-74.

Notes: The effect of temperature on the development of the hemispherical scale, Saissetia coffeae (Walker) (Homoptera: Coccidae), was studied. Insects were reared on potato sprouts (Solanum tuberosum L.) at 5 different constant temperatures (18, 20, 24, 28, and 30degreeC). Results showed that an increase in temperature within limits accelerated the rate of development of all stages of the hemispherical scale. The developmental duration of the hemispherical scale from egg to adult at 18 and 28degreeC were 95.5 and 51.3 days, respectively. Nymphal scale continuously reared at 30degreeC failed to produce adults. The optimum development temperatures of the hemispherical scale were 24-28degreeC. Temperature influences the reproductive capacity of the hemispherical scale. Lower temperatures increased egg production of the scales. There was a high correlation between temperature and growth rate for all stages of the scale. Their low developmental threshold temperature (Tb) and thermal summation (K) were: 7.1degreeC and 270 DD in the egg stage; 11.9degreeC and 43 DD for crawlers, and 4.1degreeC and 555 DD for secondary instars, respectively. The life cycle of the hemispherical scale on cycad (Cycas taiwanian Carr.) was observed. The scale produces 4-5 generations per year in Taichung, west-central Taiwan.