Preliminary research on habitat selection of Chrysopa septempunctata in farmland in central Hebei Province
冀中农区大草蛉（Chrysopa septempunctata）栖息地选择

The study is on the distribution dynamics and habitat selection of C. septempunctata which is the main predator in crop fields in North China. The result shows that: firstly, C. septempunctata is inclined to the weed habitats; secondly, the distribution of C. septempunctata in the weed is stable, and it is affected directly by the width of weed, with 1m width of weed having larger density of C. septempunctata; thirdly, the forest belt plays a positive role in the distribution of C. septempunctata, and the function extents of forest belt is different along with the structure of forest belt; fourthly, forest belt becomes an important habitat in the later period of crop growth.