4Marshall E; J Pa * , MoonenA C b. Field margins in northern Europe : their functions and interactions with agriculture[J]. Agriculture, Ecosystems and Environment, 2002,89 : 5- 21.
5Steve D Wratten, Mike H Bowie. Field boundaries as barriers to movement of hover flies (Diptera:Syrphidae) in cultivated land[J]. Oecologia, 2003,134 : 605 - 611.
6Sotherton N W. The distribution and abundance of predatory arthropods overwinlering on farmland[J]. Annals of Applied Biology, 1984,105:423-429.