Quantifying the danger for Parnassius nomion on Beijing Dongling mountain

It is the major task of the researches of conservation biology to explore species existing necessary conditions and endanger mechanism [1]. Presently, population viability analysis models mainly focus on a single species and few of them take into account the influence of inter-species effect to aimed species [2][3]. It is more difficult to apply traditional population viability analysis to insects, as compared to birds or mammals. First, insects have complex life histories, small body and various species. For animals that have body length between 10m and 1cm, the number of the species increases by 100 times with the body length shorten by 1/10 [4]. Biologists' knowledge is far from completely understanding insect species, or even the number of insect, because it is very difficult to obtain the life parameters of wild insect populations. Second, biologists are accustomed to study the key species of the community, which are often the topmost taxa in biology chain or the dominant species in communities. These insect species are rare to be found playing a key role independently in ecosystem maintenance or community succession. Last, many insect species have become extinct before people know them well. The efficient and comprehensive approach is required to detect why the population of some insect specify is descending and what kind of protective strategies should be applied. In this paper, we have proposed the competition index of Parmassius nomion species by combining the aimed species population dynamics with the diversity index. The results have shown that the alteration of competition index is able to detect the danger of shrinking population.