Watermelon Mosaic Virus


  • Cucurbits


Watermelon Mosaic Virus is a Potyvirus spread by aphids. It is a concern from June  (or earlier if winter was mild or crops are grown in high tunnels) until the end of the season.

  • Infection occurs when virus-carrying aphids feed on healthy plants.
  • Overwinters in perennial weeds or alfalfa.


Symptoms include stunting, leaf malformation, yellowing or light green mottling, marginal chlorosis, and dwarfed, mottled, or spotted fruit. Fruit may also form warts, or raised blister-like areas.


This disease is widespread in Utah watermelon and squash production and occasional in cantaloupe.

  • Watch for symptoms starting in June until the end of the season.
  • First symptoms are often seen on field edges.
  • Monitor aphid activity starting in June
  • Control weeds.
  • Rotate crops.
  • Use resistant varieties when available

Insecticides for aphids are of limited value to control this disease.









Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.