Approach to the Reasons of Tomicus Piniperda (L. ) population Epidemic
Ye Hui ( Institute of Ecology and Geobotany, Yunnan University)
Form view of the population system point, the relationship between Tomicus piniperda and Yunnan.pine, and the comprehensive influence of a few factors on the population outbreaking were analysized systematically in this paper. It is suggested that, a number of Yunnan pines declining severely is one of the essential conditions for the pine shoot beetle population to increase strongly before the epidemic. As the pine shoot beetle get into epidemic phase, the pine shoot beetle is able to attack and kill the healthy trees, the populstion size thus become a major factor promoting the greater damage. climate, the host resistsnce, forest conditions and forest management play an important role in the population fluctuating. Especially, the climate in Kunming is quite advantage of the developing and breeding of the pine shoot beetle, so suggested, to be a main reason for the insect epidemics in short term.