Spatial pattern of abundance of the black bean aphid, Aphis fabae, in Britain.
Populations of Aphis fabae were monitored in the UK in 1969-86 on its primary winter host (Euonymus europaeus), on the 2 principal secondary summer crop hosts (Vicia faba [faba beans] and sugarbeet) and during the spring, summer and autumn migrations. Changes in the mean spatial pattern of abundance during a single annual cycle reflected a sequence of changing host plants. The longer-term dynamics and survival of the aphid depended on the spatial pattern of abundance in the non-crop environment. Thus, the wide distribution of wild hosts in late summer affected the numbers of autumn migrants, and the regional variation in abundance of E. europaeus affected the success of the aphid in finding sites for overwintering eggs. The results are discussed in relation to pest forecasting.