Squash vein-yellowing virus (SqVYV)
Silverleaf whitefly (Bemisia tabaci)
United States (Florida, Indiana), and Puerto Rico
SqVYV symptoms manifest as vein-yellowing in squash and vine decline in watermelon. Watermelon symptoms appear initially as chlorotic leaves, followed by browning and collapse of the entire vine within a few weeks. Symptoms develop more rapidly as fruit matures. Affected fruit may exhibit internal rind and flesh discoloration.
CONDITIONS FOR DISEASE DEVELOPMENT
SqVYV is transmitted in a semi-persistent manner by the silverleaf whitefly (Bemisia tabaci), which can transmit the virus for twenty-four hours. Host range is limited to the cucurbit family. The curcubit weeds balsam-apple and creeping cucumber can harbor the virus asymptomatically.
Avoid planting near SqVYV-infected cucurbit fields, eliminate wild cucurbit weeds and immediately incorporate infected crop debris following harvest. Implement a comprehensive insecticide program, crop rotation and a host-free period. Silver plastic mulches are effective in controlling other whitefly-transmitted viruses and may help to control SqVYV.