It seems likely that both introduction of saliva from the leafhopper and mechanical wounding by stylet movememt is necessary to cause the injury, which is a saliva-enhanced wound response associated with vascular blockage. The net result blockage of phloem transport. Gross symptoms of hopperburn probably result from this phloem blockage and subsequent accumulation of photoassimilates in leaves. This interacts with other stresses, such as drought. Hopperburn shows up as a browning and necrosis along the margins of potatoes.
Damage varies with cultivar.
In beans, it can cause a curling of the leaves, stunting, reduced root systems, and reduced yields and quality. Greatest damage comes from feeding on young plants. In alfalfa, it causes a distinctive V-shaped yellow wedge, typically first in the terminal leaflets. However, hopperburn symptoms result from the plant's response to the feeding. Therefore, responding to the damage by spraying is not the best option.