When the traps were checked, researchers found psyllids bearing the marker chemicals, indicating the pests had traveled from abandoned groves to active ones. Laboratory analysis revealed that some of these psyllids carried the bacterium that causes greening disease.

Researchers also took leaf samples from citrus trees and found the presence of greening was about the same in abandoned and managed groves. Other members of the research team were Siddharth Tiwari, Hannah Lewis-Rosenblum and Kirsten Pelz-Stelinski, all with UF’s entomology and nematology department.

Stelinski added that as-yet unpublished findings showed the insects could fly up to 1.25 miles in 10 days, and could probably travel farther over time.

“So you don’t necessarily need to be right next to an abandoned grove to be at risk,” he said.

Currently, the state is asking local property appraisers to urge landowners to remove or destroy untended citrus trees by offering tax incentives to do so, said Mike Sparks, executive vice-president and chief executive officer of Florida Citrus Mutual, Florida’s largest citrus grower trade organization.

“Even though we’ve had some success, it’s not nearly enough,” Sparks said. “This study could help us mold public policy.”

Sparks said he hopes that the UF research will persuade state and local officials to take further action to reduce the amount of abandoned citrus acreage.

“We have a $9 billion industry and 76,000 jobs at stake,” Sparks said. “Abandoned groves are putting all of that at risk and policymakers need to know that.”