Damage symptoms
The yellow rose aphids usually live in young unfolded leaves. Nymphs and adults extract nutrients from the plant and disturb the balance of growth hormones. As a result, the plant’s growth is retarded giving rise to deformed leaves. Retarded growth and defoliation reduce yield.
Plant sap is rich in sugars, but has a low protein content. Aphids therefore need to extract large quantities of sap to get sufficient protein. The excess sugar is secreted in the form of honeydew, making the crop and its fruit sticky. Black sooty moulds grow on this honeydew, contaminating fruit and ornamental crops. At the same time, photosynthesis in the leaves is reduced, affecting production. The yellow rose aphid is also a vector of several viruses attacking strawberries and roses.