By Clint Thompson
The potential of spotted lanternfly (SLF) to transmit Pierce’s disease (PD) is a problem for Georgia grape producers. That’s because the insect will eventually make its way to Georgia, believes Phil Brannen, University of Georgia (UGA) Cooperative Extension fruit disease specialist.
“It’s another thing that may be able to vector Pierce’s disease. This is very early in the process of looking at that. There’s only one report so far that indicates that it might be a vector of this bacteria that causes Pierce’s Disease,” Brannen said. “I guess I’m ringing the alarm bells about it because it’s going to be in Georgia probably in the next year or two. It’s already in Tennessee I think, and I believe in North Carolina. It’s just a matter of time before it’s here. We’re going to have to deal with it.”
Pierce’s disease is caused by a bacterium that is usually transmitted by numerous sharpshooter insects, including the glassy-winged sharpshooter. It clogs the grape xylem, cutting off nutrient and water flow.
UGA Extension Viticulture Blog
Brannen wrote in the UGA Extension Viticulture Blog that “diseased plants are not preferred by the SLF, and in addition, nymphs do not do as well on PD-infected plants. Based on previous studies on peach and other plants, the issues with nymph feeding and development and even preference for healthy host is not a surprise. However, even low levels of transmission will be sufficient to cause problems.”
Brannen added that assuming that SLF can feed on older, larger tissues, the vines will likely be more susceptible to infection. He suspects the introduction of SLF will increase PD wherever it is found.
“The insect swarms and it can actually kill a grapevine outright just from the way it comes into a vineyard, if you don’t kill the insect. We can kill the insect. It’s going to be difficult and just something else to deal with but if it transmits Pierce’s Disease, that makes it even more important that we realize even low populations of the insect maybe pretty detrimental.
“There’s still much to be learned but yet another pest we’re going to have to deal with.”