The Ecology Research Of Natural Population Of Coniatus Steveni

In this paper, Coniatus steveni Capiomont has been studied in following aspects, life tables of natural population, reproduction biology, the spatial distribution, and cold resistance. The main results and conclusion are as follows.Life tables of the first and second generation of Coniatus steveni were constructed based on data both from indoor and field observation. The life tables showed that accumulative mortality of the first generation is 87.6%, higher than the second generation (77.9%). One of the main mortality factors at larval stage was rain, and parasitism at pupal stage. For the second generation, the highest mortality appeared at egg stage (51.7%), and the mortality of the 1st-2nd larval stage was followed (34.77%). Natural enemies were the main mortality factor at larval stages, and parasitism was the main cause of dying at for the pupal stage. The survival curve of the two generation was of Deevey III, where mortality was higher at early stages (egg, 1st instar and 2st instar larvae). The population trend index, I was 4.56 for the first generation, which suggested population increasing, and 0.4512 the second generation, which suggested population declining.. Fecundity studies showed that the overwintering females laid more eggs than the following generations, in the order from high to low by 202.8 eggs for overwintering females, 76.46 eggs for the first generation females, and 7.60 eggs for the second generation females.All measures used showed the clumped spatial pattern of dispersion of individuals in egg, pupa, and adult stages, but the regular spatial pattern of dispersion in larval stages.There was no significant difference inhe super -cooling point and the freezing point between male and female. But significant differences were exhibited between insects in different dates. The super-cooling point and the freezing point of the adult was increased with the season.