STUDY ON THE EFFECT OF SUPPRESSION OF NATURAL ENEMIES UPON MASSON PINE MOTH AT LONGSHAN FOREST FARM, ZHEJIANG PROVINCE

Biotic factor is a very important factor in insect population dynamics, which is also a necessity in the research of IPM of masson pine moth Dendrolimus punctatus. The results are as follows:There are a lot of natural enemies of masson pine moth, including spiders, insects, microorganisms and birds. They form a complicated complex of natural enemy. There are several lethal factors in the life table, which has been conducted for two years (1984-1985). 78% of the larvae are killed by predators and migration etc. after egg hatching, which form a main lethal factor in the life table. According to the systematic investigation on the influence of natural enemies. Biotic factor is supposed to be the main factor in the population dynamics of masson pine moth in 1984-1985.