Abstract
A method for estimating population changes of Aphis fabae Scop. on bean plots is described. This involved the classification of bean stems in the field according to five arbitary classes of infestation and the removal to the laboratory of ten samples of each class of infested stem for the estimation of their Aphid numbers. A simple volumetric method for counting large numbers of A. fabae is described and the results obtained from three bean plots are presented.