It appears to be related to a bacterium transmitted by the potato psyllid's relative, the citrus psyllid.

ECONOMIST: Plant disease

Earlier this year researchers in New Zealand began investigating a psyllid infection in glasshouses growing tomatoes and peppers (plants closely related to potatoes).

ECONOMIST: Plant disease

Part of the answer is an insect called the potato psyllid.

ECONOMIST: Plant disease

But the potato psyllid is merely the vector.

ECONOMIST: Plant disease