Abstract: The study on the development, survivorship and reproduction of Kerria yunnanensis on 4 kinds of host trees indicated that in natural environment, the initial K. yunnanensis population density varied from 181.17 individuals on Dalbergia obtusifolia to 145.27 individuals on Ficus facemosa per cm², realized sex ratio varied from 0.24 on D. obtusifolia and F. cunia to 0.19 on D. balansae, accumulated population mortality from larval to adult varied from 90.03% on D. balansae to 87.05% on F. cunia, and development period from larval to adult ranged from 156 days on D. balansae to 140 days on F. facemosa. The oviposition of K. yunnanensis varied from 536 eggs on D. balansae to 345.86 eggs on F. facemosa, female adult mass varied from 12.62 mg on D. balansae to 9.03 mg on F. cunia, and basic reproduction rate varied from 48.51 on D. balansae to 32.79 on F. facemosa. D. balansae was the most suitable host plant for K. chinensis summer life cycle.

Key words: Stipa breviflora, fractal dimension., desert steppe, semi-variance function