Increased population of the aphid Aphis pomi at a motorway: Part 1—field evaluation

Abstract

At a motorway near Basle, a high infestation of hawthorn Crataegus spp. with the green apple aphid Aphis pomi can be observed every year, whereas plants some distance away are much less infested. In the present paper, the population development of the aphids was examined at different sites with respect to the motorway. The results suggest that a reduced efficiency of natural enemies at the motorway might be an important factor contributing to the increased infestation, but other factors such as changes in host plant biochemistry must also play a rôle.