关键词: 花椰菜地, 节肢动物, 植食性害虫, 捕食性天敌, 群落结构

Abstract: 【Objective】The objective of this study is to reveal the effects of different control measures on characteristics of the arthropod animal community in the cauliflower field and provide a theoretical basis for pest control as well as protection and utilization of natural enemies. 【Method】The test ground of this work was divided into biological pesticide control area, chemical pesticide control area and non-pesticide control area. Five random sampling points were picked out and the numbers of all plants and arthropods on the test ground were recorded. Glass bottles with washing powders and water were placed on the set point of the field. The number of arthropod species in the ground was investigated. Cauliflower arthropod community in plots with different control measures were analyzed according to results. 【Result】There were 87 arthropod species in Guangzhou’s cauliflower field, including 29 insect pest species, 54 predator species and 4 neutral insect species. The control measures could obviously affect the diversity of species and the amount of each species of the arthropod communities. In non pesticide control area, the numbers of predators, insect pests and neutral insects were higher than those of the two pesticide control areas. The relationship of arthropod specie numbers and individual numbers among different areas was: non pesticide control area＞the biological pesticide control area＞the chemical pesticide control area. The dominant concentration of plant herbivore functional groups in cauliflower was at the minimum level at seeding stage and reached the maximum level at maturity stage. The dominant concentration of predatory natural enemies in different pesticide control areas was also relatively low at seedling stage. The concentration of the natural enemies remained at a similar level through different growth stages of the cauliflower in the non pesticide control area. On the other hand, the dominant concentration of predatory natural enemies fluctuated through different growth stages in pesticide control area. Cauliflower arthropod animal community varied at different growth stages and areas with different control measures. During the whole growth period, the species with the dominance index larger than 0.1 were Bemisia tabaci, Myzus persicae, Plutella xylostella, Pieris rapae, Pirata procurvus, Pardosa pseudoannulata and Coleosoma octomaculatum. The indices of cauliflower arthropod community diversity varied in different control areas and at different growth stages. Community overall diversity index (H′) increased following the cauliflower growth and reached maximum at late stage. These results coincided with the development of the field community. The trend of diversity index with different control measures was: non pesticide control area＞biological pesticide control area＞chemical pesticide control area. The variation of evenness index among different growth stages and different control measures was small. The variation trend in diversity of pest sub-communities and overall community was the same. The diversity index reached the maximum level in the late-mid period of cauliflower growth stage. The relationship among diversity indices with different control measures were: non pesticide control area＞biological pesticide control area＞chemical pesticide control area, which reached the minimum level at seedling stage of cauliflower in chemical pesticide control area. The evenness at cauliflower seedling stage was the maximum, and then decreased with the growth of cauliflower. In each growth period, the diversity of predator sub-community with different treatments remained relatively stable. The investigation results of the arthropod in the testing ground showed that the killing of the ground arthropod was larger in the two treatment areas. At the same time, it was possible to have a certain effect on the colonization of natural enemies at the early stage of the predatory natural enemies, according to the number of ground surface arthropod and the number of predatory natural enemies. Correlation of spiders with plant herbivore，neutral insects and predatory insects was significant. Correlation between predatory insects and neutral insects was also significant. These results indicated that between these functional groups in the number of compatibility or follow the effect. The correlation between predatory insects and insect herbivores was non-significant. 【Conclusion】The control measures could effectively reduce the population of pests, but also reduced the number of natural enemies. Neutral insects on ground surface would be helpful to early colonized predators. Chemical control could severely affect arthropod community of the cauliflower field, while the biological pesticide control has less influence on arthropod communities compared with the chemical pesticides.

Key words: cauliflower field, arthropod, insect pest, predator, community structure