Effects of Field Location and Cereal species on the number of grain aphid (Sitobion avenae F.) and its parasitoids (Hymenoptera parasitica)

Abstract

The objective of the present study was to determine whether field location in an agricultural landscape affects the numbers of grain aphid and its natural enemies – parasitoids. The experiment was performed in the years 1995 – 1997 and 2000 in rye and winter wheat plantations near the city of Bydgoszcz (northern Poland). It was found that the populations of S. avenae were more numerous in cropland adjacent to shrubs, orchards and boundary strips than in plantations located within other cultivated fields. In addition, greater numbers of Hymenoptera parasitica were obtained while rearing them from the aphid colonies collected from these plantations.