Abstract:

Ericerus pela is an important resource insect with great economic value. The white wax excreted by this insect is an important chemical raw materials which is widely applied in some of chemical industries. The 6 generation agespecific life table showed that the fecundity of Ericerus pela was very high, with 8 000～12 000 egg·♀ -1. However, its death rate was high, female mortality was about 99% and male mortality was more than 96%. The high fecundity and the high death were unique characters of E. pela natural population. The mortality at egg average was 9.58%, and the mortality of the 1st instar nymph was 85.25%，about 70% of total mortality in a generation. About 80% of new hatched larvae died during the period when these nymph crawl and seek suitable leaf of host tree to live on. The mortality of the 2nd instar nymph was 45.50%, 10%～15% of a generation mortality, and death peak occured in the period when they moved from leave to branch to live on. The mortality at adult stage was average 94.64%, which was 2%～5% of total mortality. In one generation, average index of population increase trend were 32Weather and natural enemy are were major death factors which affected natural population size. Before E. pela live on branch, weather was the key factor of nymph death. Most of nymph were blew away by wind or washed out by rain, because the nymph had poor defense capability. After the insect lived on branch, wax excreted by 2ndinstar male larvae covered on themselves body, female body gradually became big and keratinized, so that their protective capability became stronger. After then natural enemy, such as parasite wasps and preyed beetles, became the main death factors.

Key words: Ericerus pela, age specific life table, fecundity, mortality, population trend index, death key factors analysis