Abstract: 13 species belonging to 2 genera of bloodsucking midges were recorded at Dandong area of Liaoning province by an ecological investigation from May to October of 1988, Culicoides nipponensis is showed to be a dominant species at the area, which occupies 35.1% of total captured number. The next dominant species is C. circumscriptus, 18.9% in total. Two new species, C. obsocuratus and Lasiohelea dandongensis, were found in the investigation. The diurnal activity of C. nipponensis peaks at an hour after sunset, its seasonal activity peaks in early Juiy and August. C. circumscriptus appears in mid-June and disappears after mid-August. C. manchuriensis also appears in mid-June bat disappears after the middle of September.

Key words: plant hedgerow, plant volatiles, Triticum aestivum, Sitobion avenae, Rhopalosiphum padi, natural enemy, biodiversity