Studies On The Component, Structure And Diversity Of Arthropod Communities In The Field Of Glycyrrhiza Uralensis In Ningxia

The arthropod species and its occurrence in the fiele of Glycyrrhiza uralensis were investigated in 2003 in the suburb of Yinchuan, Ningxia, China. In this paper, the series characteristics of arthropod, that is , the composition of species, dynamics of arthropod community and populations of main species of insect, and correlation of main species considered as biological control agents of Glycyrrhiza uralensis were studied. The results were as follows:(1) The arthropod species in the field of Glycyrrhiza uralensis were divided into three nutritional classes, that is basal species, intermediate species and top species. 74 species of arthropod on Glycyrrhiza uralensis from 39 families belonging to 9 orders were collected and identified, and 48 species of them from 25 families were the basal species. The dominant species of pest were Diorhabda tarsalis Weise, Phyllotreta vittula Redtenbacher, Loxostege vertical is Linnaeus, Aphids and Mirids etc. The relative abundance of basal species , intermediate and top species were 0.859613, 0. 123726 and 0. 016661, respectively. The diversity index such as Simpson index(J), Shannon-Wiener index(H' ), Brillouin index(H), Mclntosh index (DMc) indicated the same trends, which showed the order: arthropod community > basal species nutritional classes > intermediate species nutritional classes.(2) There was a regulatory dynamic of arthropod community on Glycyrrhiza uralensis with the time series throughout the year. The basal species and the arthropod community had the same trend in terms of their individual numbers, and had two peaks occurring in the same time. The individual numbers of arthropod community were affected by those of basal species. The analysis of the population trend in structure of arthropod showed that the diversity index and evenness had the same trend, and that the basal species was the dominant species in the arthropod community on Glycyrrhiza uralensis.The results of Path Analysis showed that increasing the diversity index, the individual numbers, evenness and decreasing the dominant concentration were most important to improve the diversity of arthropod community.The Cluster Analysis and Principal Components Analysis were also used to evaluate development of community structure and the important position of pest in the arthropod community on Glycyrrhiza uralensis.(3) 45 couplets formed by 10 species of arthropod were analyzed by CorrelationAnalysis, and 18 couplets of them showed a significant correlation. There was an extremely significant correlation between Diorhabda tarsalis and Blister beetles, Diorhabda tarsalis and Spiders, Aphids and Ladybirds. Their correlation coefficients were -0.7930,0.7947 and 0.8259, respectively.The Pearson product-moment correlation analysis showed there was 1 couplet had an extremely significant correlation between Aphids and Miridae, and the Pearson product-moment correlation coefficient was 0.643. There was 5 couplets had a significant correlation between Diorhabda tarsalis and Spiders, Miridae and Spiders, Blister beetles and Lacewings, Blister beetles and Spiders, Lacewings and Spiders. Their Pearson product-moment correlation coefficients were 0.588,0.632,0.610, -0.582 and - 0.593, respectively. The Spearson rank correlation analysis showed that 4 couplets of them had an extremely significant correlation between Diorhabda tarsalis and Blister beetles, Aphids and Miridae, Aphids and Predacious bugs, Miridae and Predacious bugs and their Spearson rank correlation coefficients were-0. 791, 0. 703, 0. 699 and 0. 676, respectively. There was a significant correlation between Miridae and Predacious bugs, Lacewings and Spiders. Their Spearson rank correlation coefficients were 0.560 and -0.563.