Abstract: Chinese white wax scale，Ericerus pela Chavannes, is an important resource insect that excretes white wax with economic value. The ecological adaptability of this scale has been disputed for a long time. In this paper, the wax excretion mechanism of E. pela was studied depending on the wax excretion and ecological observation of this scale in Emei mountain of Sichuan province, and Kunming and Zhaotong of Yunnan province. The results showed that both the wax excretion amount and the mortality of E. pela in severe environment were higher than those in normal environment. So wax excretion amount was not a appropriate index for evaluating the ecological adaptability of the scale as traditionally considered. The reasons of breeding reproductive females in high mountain areas and producing white wax in low mountain areas were analyzed also in this paper. The areas suitable for the growth of the scale had the following climatic conditions: the annual average temperature was 11℃-16℃, the annual rain fall 800-1 200 mm/a, the annual relative humidity about 75％ and the annual light hour 1 900-2 500 h/a. The results suggested that wax excretion of E. pela was an ecological strategy and a protective response to severe environment.

Key words: Ericerus pela, wax excretion, ecological adaptability, area suitable for growth, climatic factors