The white grub, Plectris aliena, was first documented near Charleston in the 1930s and has caused few problems in South Carolina, but in a small area in North Carolina, it has caused severe damage to sweet potatoes and keeping it confined to that area has been an ongoing challenge for the past few years.

Sweet potatoes have become a superstar among health-conscious Americans and for good reason. Consumption of sweet potatoes has been linked to reduced heart disease, and to contributing to improved immunity to a number of other disease causing pathogens.

And, its nutritional value ranks among the top crops grown anywhere in the world.

Unfortunately, sweet potatoes are not marketed based on their nutritional or medicinal value, instead they are still marketed primarily on how they look.

White grubs, or plectris grubs, make sweet potatoes look bad, very bad.

Though the burrowing damage, caused by feeding of these insects on sweet potatoes, doesn’t reduce nutritional or health value of the crop, it can virtually destroy its marketability.

When plectris grub first showed up in Columbus County, N.C., it made an immediate impact, and not a good one, on growers there. The more immediate concern was to figure out how to prevent the insects from moving into even more highly intensive sweet potato growing areas of the state.

“When George Wooten found these insects in his sweet potatoes in 2006, that was the first time we knew we had a problem, or even that the pest was present in North Carolina, says North Carolina State University Entomologist Mark Abney.

“Since then we have had near catastrophic damage on sweet potatoes in some fields,” he says.

Since it was first documented on sweet potatoes in North Carolina this pest has caused an estimated $16.5 million in losses, or about one-tenth the annual value of sweet potatoes in the state.

Despite intense research efforts, there remains no definitive chemical control for these pests.

In recent research, plectris grubs have been found in corn, soybean and peanut fields, creating significant concern but so far no real damage.