Watermelon chlorotic stunt virus (WmCSV) in watermelon taken from infected fields near Yuma, Arizona in 2025. (Photo by W.M. Wintermantel, USDA-ARS)

Unraveling a Mysterious Virus

ARS researchers have found a new virus playing hide and seek with the melon industry.  In 2023, unusual symptoms of infection were observed in melon and watermelon plants from Arizona and California. ARS scientists in Salinas, CA, sampled infected plants and used gene sequencing technology to identify the culprit – watermelon chlorotic stunt virus (WmCSV).  

This virus is transmitted by whiteflies, and can cause significant yield loss, particularly in watermelon, but it also infects all types of cucurbit (melon, pumpkin, squash, and cucumber) crops. Learn more...

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.