The Preliminary Study Of The Relationship Between Three Kinds Of Predator Natural Enemy Insects And Pests At The Desert Transition Zone And Neighbouring Cotton Field

A systematical investigation was carried out in desert transitional zone and neighbouring cotton field in Shache County, Xinjiang from April to August, 2006.Studied the community composing and time dynamic of three kinds of predatory natural enemy insects and pests in cotton field and desert transition zone,dominant enemy insects and pests in two habitats,Similarity indices and niche of three kinds of predatory natural enemy insects and pests community in different habitats .The results were concluded as follows:1.There are 5033 arthropods were collected in the desert habitat,including 12 orders,99 families,206 species.The species and individuals of phytophagous insect are largest. There are 113549 arthropods were collected in the cotton field,including 12 orders,48 families,83species.The species of predatoruy insect are largest ,and individuals of phytophagous insect are largest.2. In total, 19 species of predatory natura enemy insects were collected in the desert transition zone and cotton field individual, the dominant species of three kinds of natural predatory enemy insects are Hippodamia(Adonia)Variegata(Goeze),Chrysoperlae sinica Tjeder,Chrysopa phyllochroma Wesmael,Campylomma diversicornis Reuter in desert transition zone,the individual's percentage of them were 71.89%. The dominant species of three kinds of natural predatory enemy insects are Hippodamia(Adonia)Variegata(Goeze),Campylomma diversicornis Reuter,Derae ocoris punctulatus Fall in cotton field. The individual's percentage of them were 69.0925%.The total of 22 species of pests were collected in the desert transition zone, Lygus pratensis and Idiocerus koreanus Matsumura were dominant species,16 species of pests were collected in cotton field and Aphis gossypii was dominant species.3.The result of time dynamic comparison of three kinds of predatory natural enemy insects and pests in cotton field and desert transition zone concluded that the desert transitional zone was species pool of three natural enemies in cotton field;the difference of pests community were not distinct in two habitats,but the desert transitional zone was not species pool of pests in cotton field.4.Similarity indices were examined in three kinds of natural predatory enemy insects and pest communities, descending sorts of groups were lacewings, bugs, pests, ladybirda. On level direction,from cotton field to four desert habitats, the comparison of similarity indicated the similarity indices of natural enemies of near cotton field was more than that of natural enemies and pests of far cotton field, the similarity indices of pest in second desert habitat was most.5.The research about time niche declared that in two habitats, the ditribution of lacewings was more homogeneous in time sequence and the niche breadth was most large; bugs to Aphis gossypii's time follow effect are much strong.Three kinds of natural predatory enemy insects and pest communities'spatial niche comparation declared that Chrysopa phyllochroma Wesmael,Campylomma diversicornis Reuter,Chrysoperlae sinica Tjeder,Derae ocoris punctulatus Fall,Hippodamia(Adonia)Variegata(Goeze),Triphleps minutus L.occupied more spatial in two habitats.Niche overlap of Hippodamia(Adonia)Variegata(Goeze) and Chrysopa phyllochroma Wesmael,Campylomma diversicornis Reuter,Derae ocoris punctulatus Fall are closed, The overlapped two occupied similary spatial resourses,which competed very seriously intense.