How to Manage Pests

Pests in Gardens and Landscapes

Viruses—Potyviruses, Mosaic viruses, Cucumber aphidborne yellows, and Lettuce infectious yellows

Symptoms of virus diseases include mottling of light green, yellow, or white areas on leaves, clearing of veins, thickening of leaves, and reduction in growth and yield. Fruit may be deformed.

Life cycle


Viruses are transmitted by insects, such as aphids, whiteflies, and cucumber beetles. Remove infected plants as soon as they are detected. It is not practical to try to control virus diseases by using insecticides to control insects. Using reflective mulches may reduce or delay infections as it helps repel insects from plants. Covering young plants with row cover can also protect them from insects.

Watermelon mosaic virus on squashWatermelon mosaic virus on squash

Mottling caused by watermelon mosaicMottling caused by watermelon mosaic

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2014 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/GARDEN/VEGES/DISEASES/cuvirus.html revised: April 25, 2014. Contact webmaster.