THE SPECIES RICHNESS AND DIVERSITY OF THE ARTHROPOD COMMUNITIES IN RICE FIELDS

Abstract The present paper deals with the characteristics of species richness and diversity of the arthropod communities in different rice fields and at various growing stages of rice based on the data ob tained from field surveys and the measurement of the community diversity. The field surveys were carried out in three different locations which represented three typical rice-growing habitats: mountainous, plain and hilly fields in the suburb of Fuzhou, Fujian Province in 1994. Shannon-Wiener's (1949) average information content(H), Hurlbert's(1971) probability of interspecific encounter (PIE) and Pielou's (1966) formula of equitability (E) were used to measure the diversity of the arthropod communities in the ecosystem of rice fields. The result showed that the species richness of herbivorous insects, carnivorous insects, spiders and total species in the community varied with different fields because of the influence of environmental variables in the habitats, and fluctuated with various growing stages of rice due to the variation of crop nourishment. Changes in the index values of H, PIE and E indicated that the cornmunity diversity and equitability also varied with space (habitats formed by the rice fields) and time (growing stages of rice). The author thinks that the results of the study could be applied to predict and forecast the population dynamics of rice pests, and to develop the rational program of integrated pest management in the specific rice fields. Discussions are also given in some detail on the methodology of measurement of the species richness and diversity of the arthropod communities in rice fields.