When population densities are high, winged individuals are produced. These individuals emigrate to new hosts. There are several factors that naturally control aphid populations. They feel this resistance may be passed on through selective breeding to the modern crisphead variety Marbello which is a cross of crisphead and butterhead lettuces. Users should carefully consider the use of soaps.
Excessive use can cause a drop in yield of the crop.
A chemical management program for strawberries was tested by Trumble et al. They found that a regular sampling plan of counting the number of aphids per plant may be used to determine when the potential damage levels reach a threshold. Blackman, R. L. and V.F. Eastop. An Identification and information Guide. Higa, S. Y. and R. Namba.