Published on 09/03/08

Pretty pest causes ugly damage

By Sharon Dowdy
University of Georgia

Despite its dainty name, the lace bug can cause major headaches for nurserymen and homeowners across the country. University of Georgia researchers recently identified a species that has never been recorded in Georgia. And, it has taken a liking to ornamental grasses.

Over the past three years, UGA entomologist Kris Braman has evaluated ornamental grasses in plots on the College of Agricultural and Environmental Sciences’ Griffin, Ga., campus. This summer, she and CAES graduate student Evelyn Carr discovered lace bugs on an experimental line of ornamental grass called Pennisetum.

Feed on trees and ornamentals, too

Lace bugs commonly feed on azaleas, chrysanthemums, cotoneasters and sycamores, Carr said, but not on ornamental grasses.

Lace bugs live on the undersides of leaves. When feeding, they stick their mouthparts into the leaf and suck out the cell contents. This causes the top side of the leaf to be discolored with white dots. They can further discolor leaves by laying their eggs on the undersides.

“They stress the plant and harm it aesthetically,” Carr said. “So on our ornamental grasses, its damage would be considered very extensive.”

Making a big problem bigger

Left unchecked, the tiny pest could have a definite economic impact on the state’s landscape industry. “Ornamental grasses have become a staple in the landscape,” Carr said. “You see them everywhere.”

Georgia nurserymen, landscapers and homeowners spend more than $1.7 million annually to control lace bugs on ornamental plants. The pest still causes more than $300,000 in damage each year.

To properly identify the new species, they sent a sample to the U.S. Department of Agriculture Systematic Entomology Laboratory in Maryland. It was identified as Leptodictya plana.

“This is a species we know very little about,” Carr said. “There’s only been one scientific paper published on it.”

Lots to learn about new species

As part of her thesis, Carr plans to determine the lace bug’s biology, origin, reproductive traits and more.

“The ultimate goal is to determine the best way to control it,” she said.

This species is closely related to the sugarcane lace bug which is a huge problem in Hawaii and South America, she said.

“It’s normally found in Texas, Mississippi, Arizona and other dry states,” she said. “Dr. Braman hypothesizes that it has increased in Georgia because of the dry weather associated with the drought.”

This lace bug species could cause problems in Georgia, but it can benefit some regions, she said.

“Out West they are looking at this (lace bug) as a good thing,” Carr said. “It feeds on bufflegrass which is considered a noxious weed there.”

Braman and Carr are raising this lace bug species in their laboratories to identify other plants it will feed on.

Sharon Dowdy is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.