Discussion on the Natural Mortality and Its Mechanism of Lac Insect (Kerria lacca)

The population natural mortality is an important index of ecology and biology for studying lac insect. The natural mortality and its mechanism of lac insect population are discussed in this paper. The results have shown that the natural mortality of lac insect is about 85%,and high mortality is one of specific character of lac insect. The main fatal factor of lac insect is the natural regulation of population. In the larval stage, the lac insect individuals with weak adaptive ability to the environment are eliminated because of individual variation determined by genetic character, which conforms the theory "spreading of risk". In the adult stage, the natural regulation of lac insect population is that individuality contend for limited space resource.