沈阳地区稻田节肢动物群落结构及群落生态研究

The constructions and ecology of arthropod community of paddies in Shenyang

通过对沈阳地区稻田生态系统节肢动物群落结构及群落生态研究。共查得 ,属昆虫纲的有 1 0个目 2 9科 66种 ,其中天敌昆虫种类有 7目 2 0科 5 1种 ,属蜘蛛纲的有蜘蛛目 1 0科 2 0种。用空间及时间生态位分析了害虫与天敌两个营养阶层间的关系。稻田生态系统节肢动物的多样性指数、均匀度与优势度分析表明 ,各类群落受外界干扰都很敏感 ,且表现一致性。依据节肢动物群落的结构及规律 ,结合沈阳地区水稻生长、栽培条件 ,用最优分割方法将稻田群落分为 4个阶段 。

Arthropod community is an important part of eco\|system of paddy field .Studies on its community are one of basic work on dynamics,forecast and optimum control of rice insect pests .The construction,alteration law,niche and diversity of arthropod community in paddy fields were primilarly conducted by the method of systematic survey in field combined with laboratory experiment,base on the data from the field investigation and experiment. Through a systematic investigation ,spot observation and indoor raising ,the arthropods in rice fields including 10 orders ,29 families ,66 species of insect(included 7 orders, 20 families , 51 species of natural enemies) as well as 10 families , 20 species of Arachnoidea were found.The dominant species of insects in Nongda, Wangjia and Damiao experimental fields are Naranga aenescens 、Delphacidae(Nilaparvata lugens and Sogatella furcifera) 、 Oxya chinensis , and these three pest species number to total species number in percentage was 81 71%, 97 08% and 80 18% respectively in Nongda ,Wangjia and Damiao experimental field .The major insect natural enemies were Ichneumonoidae 、Nabit stenoferus、Paederus fuscipes、Libellulidae and Coccinellidae, and there seasonal abundance changes with the insect pest population dynamics. Clubiona japonicola 、Erigonidium graminicolum 、Misumenops tricuspidatus、Tetragnatha extensa and Argiops bruennichiithat were the dominant species of paddy spider sub communities in three fields in order ,amounted to 89 92% of the total ones, especially the first three species amounted to 75 53%. The relationships between two trophic levels of pests and natural enemies were analysed by temporal and spacial niche. According to the temporal niche widths value B(I) , it could be seen that the time that Oxya chinensis harmed rice was longer than Naranga aenescens、Delphacidae . The occurrence period of Coccinellidae、Itoplectis narangae was longer than the other natural enemies . Clubiona japonicola、Erigonidium graminicolum happened much longer among spiders. The time niche overlapping values showed the synchronous degree that insects and nataral enemies occured .In general, temporal niche overlapping value of insect pests and natural enemy was very high, about >0 9500, perhaps this was a distinguishing feature between the northern paddy system and the southern one. The analysis of community diversity, evenness and dominance showed that ,three paddy communities were all senitive to outside interference, and appeared consistantly. The results showed that H′ value of paddy arthropod was low (<3 0) and this indicated that the stability of the community was poor . D value of pests was high and the dominance was large at the earlier stage of rice growth ,then, D value of insect natural enemy increased and the d value of insects pests decreased with the growth of crops and the increase of the number of natural enemies. The number of insects and natural enemies was little and the E value was small and the evenness was poor at the initial stage of rice growth. But the E value inclined to 1 with the increase of the insects psets and the natural enemies population. It was time that the communities of the whole paddy system were evenest. According to the construction and fluctuation of paddy Arthropod communities and the rice growth and the cultivated condition , the paddy communities were divided into four periods by using the optimal point analysis method . The characteristics and management strategies of pest communities in different peroids were discussed . The characteristics in each peroid of Arthropod communities were seen according to the four peroids combined with climate factors and the season change of main insects and natural enemies. The early of may to the end of June, from rice transplanting rice seedlings to tiller stage, Arthropod communities of paddy system is at the beginning peroid. Only the first generation of Naranga aenescens was abundant at