While we have all been bracing for the potential onslaught of silverleaf whiteflies, the one bright spot was that the viral diseases that caused the bigger disasters in 2016 had not been seen in 2017. This is no longer the case.
Cucurbit leaf crumple virus, which decimated snap beans and squash last fall, has been verified from squash in South Georgia (the week of Aug. 1). As with the whiteflies, this first occurrence is earlier than the disease was detected last year. This has also occurred at lower whitefly densities than last fall, which suggests the potential that a fair percentage of whiteflies may already be carrying the virus.
We will be keeping an eye on both the whiteflies and virus over the next few weeks to see just how widespread both may be. Based on reports from row crops, whiteflies are already more broadly spread across South Georgia than their normal distribution and have been at detectable levels for more than a month (or two) in some areas. The populations are far higher and the distribution much wider than normal for this time of year. The broad heavy rains we received occurred after the whiteflies established in many crops, thus, the rain helped to keep numbers level, but we are already seeing rapid population increases with just a few days of hot dry weather. The addition of virus to this situation does not bode well for production of susceptible crops this fall.