False top roll (potato aphid)

Macrosiphum euphorbiae

Symptoms

• Symptoms in localised patches in the field
• Leaves roll from the middle vein upwards
• Dark purple colouring of the leaves (variety specific)
• Symptoms only on leaf layers in the top of the plant
• Necrosis of leaf borders and finally the death of the plant

Spread

• Transmitted via the potato aphid
• This species secretes toxins in its saliva, which cause the top roll
• Damage occurs in June with symptoms visible until July
• False top roll is not transferred via seed tubers

Possible confusion with

• Leaf roll virus (PLRV)