Clemson University’s Department of Plant Industry (DPI) is updating the boundaries of the Asian longhorned beetle (ALB) quarantine in Charleston and Dorchester counties following years of intensive surveying and monitoring, reflecting both new detections in one area and significant progress toward eradication in another.
The revised quarantine will take effect Aug. 23, 2026. Under the updated boundaries, the quarantine area centered around Hollywood will expand, while the quarantine area in Mount Pleasant will be reduced based on extensive survey data collected by Clemson University, the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) and state and local partners.
The changes are designed to ensure quarantine boundaries accurately reflect the current distribution of the invasive pest while continuing to protect South Carolina’s forests, homeowners and forest products industries.
“These changes demonstrate that our eradication program is working exactly as intended,” said Steven Long, assistant director, Department of Plant Industry. “Years of intensive surveys have given us a much clearer picture of where Asian longhorned beetle remains active and where it has been successfully eliminated. By adjusting the quarantine accordingly, we’re focusing resources where they’re needed most while reducing restrictions in areas where the risk has declined.”
The Asian longhorned beetle is an invasive wood-boring insect native to Asia that attacks and eventually kills hardwood trees, including maple, elm, birch, willow, sycamore, poplar and several other species. Once established, infestations can have devastating ecological and economic impacts on urban forests, residential landscapes and commercial timber resources.
The beetle was first detected in South Carolina near Hollywood in June 2020, marking the first known infestation in the southeastern United States. A second infestation was discovered in Mount Pleasant in 2025 during routine survey work.
Since the initial detection, Clemson DPI and USDA APHIS have carried out one of the largest invasive insect eradication efforts in South Carolina’s history. As of July 10, 2026, survey crews have inspected more than 596,000 trees, identifying 13,140 infested treesacross the quarantined areas. To stop the beetle’s spread, crews have removed 9,174 infested treesand an additional 25,236 high-risk host treesthat could harbor undetected beetles. The work represents years of coordinated surveying, tree removal, treatment and public cooperation.
Those efforts have produced measurable results. In Mount Pleasant, intensive delimitation surveys following the 2025 discovery have shown the infestation is much smaller than initially feared, allowing officials to reduce the quarantine area. In Hollywood, continued survey work has identified additional pockets of infestation outside the original boundary, prompting an expansion of the quarantine to ensure all known risk areas remain regulated. Officials say these changes reflect improved understanding of the beetle’s distribution—not a setback in the eradication effort—and demonstrate how ongoing surveillance guides management decisions.
The quarantine restricts the movement of hardwood firewood, logs, stumps, branches and other regulated materials that could spread the insect to new locations. These measures help protect homeowners, municipalities, the forestry industry and agricultural trade throughout South Carolina and beyond.
The updated quarantine boundaries are intended to safeguard counties outside the regulated area while supporting in-state, national and international commerce by ensuring potentially infested materials remain within the quarantine unless properly handled.
Property owners within the quarantine should continue to follow all movement restrictions and remain vigilant for signs of Asian longhorned beetle, including perfectly round exit holes about the diameter of a pencil, shallow egg-laying pits in tree bark, excessive sawdust-like material at the base of trees or branch crotches, and unusually large black-and-white beetles with long banded antennae.
Although substantial progress has been made over the past six years, officials caution that eradication requires years of continued monitoring because beetle populations can remain undetected within trees for extended periods.
“We appreciate the continued cooperation of residents, property owners and local governments,” said Steve Cole, director of Clemson Regulatory Services. “Their partnership has been essential to the progress we’ve made and will remain critical as we work toward complete eradication of Asian longhorned beetle from South Carolina.”
Residents can view maps of the revised quarantine boundaries and learn more about Asian longhorned beetle by visiting the Clemson Regulatory Services website.
About the quarantine changes
The revised quarantine includes:
- An expanded Hollywood quarantine area encompassing portions of Charleston and Dorchester counties based on recent survey findings.
- A reduced Mount Pleasant quarantine area reflecting successful delimitation surveys that better define the extent of the infestation.
The updated quarantine becomes effective Aug. 23, 2026, and remains in effect until modified by Clemson University’s Department of Plant Industry.
Asian longhorned beetle eradication effort by the numbers
(As of July 10, 2026)
- Trees surveyed: 596,023
- Infested trees detected: 13,140
- Infested trees removed: 9,174
- High-risk host trees removed: 25,236
- Original Hollywood quarantine (2020): 12,827 acres
- Mount Pleasant quarantine established (2025): 313 acres
- Infested tree removals in the original Hollywood quarantine: 9,039
- Infested tree removals in the Mount Pleasant quarantine: 135
For questions regarding the quarantine or Clemson’s Asian longhorned beetle eradication program, contact Steve Cole, director of Clemson Regulatory Services, at scole3@clemson.edu.
