Community component and principal component analysis of the complex ecosystem of spider mites and their natural enemies in bean fields
Author of the article:CAI Ren-Lian** JIN Dao-Chao*** GUO Jian-Jun YI Tian-Ci WANG Jia-Lin
Author's Workplace：Guizhou Key Laboratory for Insect Pest of Mountainous Agriculture, Institute of Entomology, Guizhou University, Guiyang 550025, China
Key Words： Phaseolus vulgaris, spider mite, natural enemy, complex ecosystem, principal component analysis
Abstract： [Objectives] To understand the community component and structure of spider mites, important pests of the bean Phaseolus vulgaris, and their natural enemies in Phaseolus vulgaris fields, and to improve methods for controlling spider mites. [Methods] From May to August 2013, systematic investigations were conducted in bean fields. Community character index and principal components were analyzed, and evaluation functions established to study the characters, temporal pattern, and stability of the insect community. [Results] 21 species, from 11 families and 7 orders, were identified in bean fields, of which Tetranychus urticae Koch and Orius similis Zheng were the dominant species. Species diversity and evenness increased gradually with crop age, but declined following an increase in the number of T. urticae which was much higher in the middle and later periods of bean crop development than in the early and last periods. Complexity was higher in the middle and later growth period than in the early and late stages. [Conclusion] Natural enemies have a great influence on this complex ecosystem. Population increases of natural enemies lagged behind those of T. urticae.