Worldwide distribution. On lettuce and chicory, ornamentals and weeds in the daisy family.
An important virus disease.
Stunted plants; light and dark green patches on leaves, margins rolled under, distorted, brown veins.
Spread is by aphids and seed (up to 40%).
Cultural control: certified seed; avoid overlapping crops; weed; collect and burn trash after harvest.
Chemical control: not effective: aphids spread the virus from diseased to healthy plants very quickly, faster than it takes an insecticide to kill them. If insecticides are needed to kill aphids, use white or horticultural oil, or soap.