TY  - JA
AU  - Vorley,V.T
AU  - Wratten,S.D
TI  - Migration of parasitoids (Hymenoptera:  Braconidae) of cereal aphids (Hemiptera: Aphididae) between grassland, early-sown cereals and latesown cereals in         southern England
PY  - 1987///
T2  - Bulletin of Entomological Research
ER  -