Data are weekly catches of flying aphids at each location during each year of the study. At each location, the count is the total of three traps that were positioned along a field edge. A trap consisted of a yellow plastic plate, mounted 20cm above the soil surface and filled with antifreeze to capture and preserve the aphids. Aphids associated with wheat were identified to species and listed separately. The remainder are recorded as ‘other aphids’ in these sheets and included many other aphid pests of crops, notably cabbage aphids. All specimens are conserved so these could be processed at a later time. Location of samples to be determined. Precise locations of the traps differed sightly each year. Coordinates are for the official coordinates for the experiment stations, so the same for each year/location. Data structure: Rows are locations and weeks within year. Columns are the scientific names of each aphid species. Values are total aphids of that species per site/date.