title: [Temporal pattern of arthropod community on cultivated alfalfa grassland].
abstract: The variation of species and diversities of the arthropod community on cultivated alfalfa grassland was investigated and studied. Principal component analysis and optimal sorting method were used to study its temporal patterns. The results showed that the difference and regularity of species richness, and the diversity and evenness of the arthropod community at different time were obvious. The numbers of the species of insect pests and their natural enemies were the most in the last ten days of June, but the peak period of individual numbers of the natural enemies was later than that of insect pests. The main factors and temporal patterns of arthropod community in the course of seasons were obvious. Based on the results, the temporal patterns of arthropod community on cultivated alfalfa grassland could be divided into four stages: before the first ten days of May, the middle ten days of May to the first ten days of June, the middle ten days of June to the middle ten days of July, and after the middle ten days of July. Considering the climatic and phenological development, the characteristics of the pests and the natural enemies occurring in each stage were analyzed, and the corresponding management tactics were discussed.
authors.affiliation: Department of Plant Protection, Gansu Agricultural University, State Key Laboratory of Arid Agroecology, Lanzhou University, Lanzhou. liuchzh@public.lz.gs.cn
authors.forename: Changzhong
authors.initials: C
authors.lastname: Liu
authors.forename: Wanxiong
authors.initials: W
authors.lastname: Wang
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wu
authors.forename: Jinwen
authors.initials: J
authors.lastname: Shang
mesh_terms: D000818:Animals; D001181:Arthropods / Q000145:classification / Q000502:physiology*; D017753:Ecosystem; D000455:Medicago sativa / Q000502:physiology*; D025341:Principal Component Analysis / Q000379:methods; D013997:Time Factors