Abstract Cucurbit yellow stunting disorder virus (CYSDV) is a crinivirus that is non-circulative, semi-persistently transmitted by the whitefly Bemisia tabaci. It multiplies in cucurbitaceous plant species but not inside its insect vector. The main pathways of CYSDV introduction and long-distance spread are through infected plants for planting. Short-distance spread is predominantly through viruliferous (infected) adults of B. tabaci. CYSDV is considered an 'emerging virus' and is increasingly recorded from a number of European, American and Asiatic countries. Infected cucurbit crops display yellowing symptoms on the leaves and this damage leads to an approximate yield reduction of 30-50% in Spain and Lebanon (Célix et al., 1996; Hourani and Abou-Jawdah, 2003). In Arizona, the outbreak of CYSDV in 2006 caused an estimated 60% reduction in marketable melon yield and a subsequent US$ 18 million loss (McGinley, 2008; James, 2011). CYSDV was added to the EPPO A2 List in 2004.