Termites in South Carolina: Species, the CL-100 and State Rules

South Carolina is where the Formosan termite was first collected on the U.S. mainland, and it's still spreading across the Lowcountry and Midlands. The state also has one of the most detailed sets of termite rules in the country, including a contract that must say in writing whether it covers Formosans. Here's the South Carolina version.

By John Updated 7 min read Termite pressure: Very heavy
Sketch map of South Carolina labeled with very heavy termite pressure

The short version

South Carolina has native subterranean termites statewide, Formosan termites established in 16 counties, mostly in the Lowcountry and Midlands, and drywood termites near the coast. Natives swarm on early-spring afternoons; Formosans swarm on evenings from mid-May to July. Termite companies are licensed by Clemson's Department of Pesticide Regulation, and home sales use the state's Wood Infestation Report, called the CL-100.

South Carolina at a glance

Termite pressure
Very heavy
Termites to know
Eastern subterranean, Formosan subterranean, Southeastern drywood
Why termites like it here
Hot, humid summers and mild winters, with native subterranean termites statewide, Formosan termites concentrated from Charleston south to Beaufort and drywood termites near the coast.
Inspection report for home sales
Official South Carolina Wood Infestation Report (the CL-100)
On this page
  1. Eight termites, two that matter most
  2. South Carolina's termites at a glance
  3. When termites swarm in South Carolina
  4. Who regulates termite work
  5. What South Carolina's termite rules require
  6. The CL-100
  7. Clemson's advice on Formosans
  8. Building new in South Carolina
  9. Questions

Eight termites, two that matter most

Clemson University's survey of South Carolina termites recorded eight species. For homeowners, they sort into three groups:

  • Native subterranean termites, the eastern and southeastern subterranean termites, are the most common and live statewide. They look so alike that it takes a microscope to tell them apart. A third native, the light southeastern subterranean termite, is often mistaken for a drywood termite.
  • Formosan subterranean termites were introduced in the 1950s. Clemson Extension entomologist Eric Benson lists them as established in 16 counties as of 2022: Aiken, Bamberg, Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Horry, Jasper, Lexington, Orangeburg, Pickens, Richland, Sumter and York, most concentrated from Charleston south to Beaufort. Infestations in York and Pickens, likely from railroad ties used in retaining walls, were treated and not found again.
  • Drywood termites are mainly a coastal issue. Clemson's records put the eastern drywood termite in six coastal counties. A second species, Cryptotermes brevis, has turned up in seven counties as far inland as Pickens and Spartanburg, but never in the wild here, only in structures.

Clemson's survey even logged a new state record: a western drywood termite colony in a couch in Greenville County. Furniture travels, and so do termites. Background on each type is in types of termites.

South Carolina's termites at a glance

Based on Clemson Extension's Home and Garden Information Center.

South Carolina termites compared
Termite Where Swarms Swarmer
Native subterranean Statewide Early spring, usually in the afternoon About 3/8 inch, dark
Formosan subterranean 16 counties, mostly Lowcountry and Midlands Mid-May to July, usually evening, toward lights About 1/2 inch, golden brown
Eastern drywood Coastal counties Seldom noticed Look for pellets rather than swarmers

A county listing doesn't mean the whole county is infested; Clemson stresses that only certain areas have established colonies. Questions go to Clemson's Home and Garden Information Center at 1-888-656-9988.

When termites swarm in South Carolina

Native swarms come in early spring, usually in the afternoon. Formosans swarm from mid-May to July, usually in the evening.

Typical swarm months for South Carolina's termites
Termite J F M A M J J A S O N D
Eastern subterranean Daytime, often after a warm rain some swarms peak peak common some swarms
Formosan subterranean Dusk, in big clouds around lights some swarms peak peak some swarms
Southeastern drywood Night, toward lights common peak

Who regulates termite work

Termite companies in South Carolina are licensed by the Clemson University Department of Pesticide Regulation (DPR). A structural company needs a DPR business license and a Designated Certified Applicator at each location, who must have two years of verifiable experience or a four-year degree. DPR has an online lookup for licensed commercial companies.

Two consumer protections are worth knowing. Structural companies must carry general liability insurance of at least $100,000, with deductibles capped at $1,000, and if coverage lapses the license is suspended and then revoked. And DPR investigates complaints: call 864-646-2150. Outcomes range from a written warning to a fine or license revocation. More in how to file a complaint against a pest control company.

What South Carolina's termite rules require

From South Carolina Regulation 27-1085, the state's standards for preventing and controlling wood-destroying organisms.

South Carolina termite contract and treatment rules
Rule What it means for you
Formosan coverage stated Every subterranean termite contract or warranty must say whether it covers Formosans, and whether that means retreatment only or retreatment plus repair
Whole-structure treatment Treatment must cover the entire structure unless conditions make it unreasonable; any exception needs the Official Waiver of Standards Form signed by the owner before work begins
Records Warranties, treatment records, waivers and inspection records are kept five years or the length of the warranty, whichever is longer
New-home pretreat warranty One year from the first application, covering damage repair and retreatment; offered for renewal for five years, at least as retreatment coverage
Transfer of pretreat warranty Must be offered to the first owner or any buyer within five years of the initial treatment, if still in effect
Warranty sales Selling a warranty without treatment is prohibited unless the Director grants a written exemption
Formosan disclosure If an active Formosan infestation is found in a structure, its presence must be disclosed

The rule also defines excessive moisture as wood at 20 percent moisture or higher, or standing water, and notes decay becomes active at 28 percent. If your house is under a bond, Clemson suggests rereading the latest contract and asking the company which termites and which damage are covered.

The CL-100

In a South Carolina home sale, the termite report is the Official South Carolina Wood Infestation Report, universally known as the CL-100 or "termite letter." Under Regulation 27-1085, it must be done by a person licensed for wood-destroying organism work under a valid business license, signed and dated with license numbers.

The regulation sets a real minimum for the inspection:

  • A visual inspection of the accessible interior, exterior, crawlspaces, utility areas and attics.
  • Sounding and probing of visibly damaged wood.
  • Moisture readings, plus a finding on whether decay is present below the first main living floor.
  • Full disclosure of damage, including damage that has already been repaired, and of prior treatments with the organism and date.

The regulation is also clear about what the report isn't: it's not a warranty against future infestation, and it doesn't obligate anyone to fix what it finds. Clemson DPR's buyer guide describes the report's two pages: the first with basic inspection information, the second with comments, areas of concern and areas that couldn't be inspected. Read page two. The national version of this report is covered in WDI inspection.

Clemson's advice on Formosans

Clemson's Eric Benson is reassuring and specific. The same products and strategies that control native subterranean termites work on Formosans, and coastal pest professionals have protected homes from them for decades. Formosan colonies can reach a million or more workers and are more likely to build above-ground nests; a 1980s Clemson study in Charleston found about 6 percent of 50 Formosan colonies were aerial.

His checklist: don't panic, don't rush into a contract, interview one to three companies, look for a good written guarantee, and have the whole house inspected, foundation to roof, not just the first floor. Treatment details are in Formosan termite treatment.

Building new in South Carolina

Regulation 27-1085 sets specific rules for new homes, and buyers of new construction can use them:

  • The final perimeter treatment. Soil next to the foundation must be treated within 90 days after the property transfers or the company is notified that final grade is complete, whichever comes first. Ask the builder who's responsible and when.
  • A one-year pretreat warranty that covers both retreatment and damage repair, renewable for five years at least as retreatment coverage, and offered to buyers within those five years.
  • Clearances and ventilation. The rule's standards call for at least 8 inches between untreated wood and soil and crawlspace ventilation of 1 square foot per 150 square feet of crawlspace.
  • Exclusions to watch. Warranties can exclude things like rigid foam or untreated wood below grade, inadequate clearance and unauthorized additions. If you add a deck or pile soil against the house, check the warranty first.

More on treatment before the slab goes down in termite pretreatment.

Questions people ask

What kind of termites are in South Carolina?

Clemson recorded eight species. The ones that matter most are the native eastern and southeastern subterranean termites, found statewide, and the Formosan subterranean termite, established in 16 counties. Drywood termites turn up mostly near the coast.

When do termites swarm in South Carolina?

Native subterranean termites swarm in early spring, usually in the afternoon. Formosan termites swarm from mid-May to July, usually in the evening, and fly toward lights.

What is a CL-100 in South Carolina?

It's the common name for the Official South Carolina Wood Infestation Report used in home sales. A licensed inspector checks accessible areas, probes damaged wood, takes moisture readings and reports damage, infestations and prior treatments. It isn't a warranty.

Does my South Carolina termite bond cover Formosan termites?

Check the contract. South Carolina rules require every subterranean termite contract to state whether Formosans are covered and whether that means retreatment only or retreatment plus repair.

How do I check a pest control company's license in South Carolina?

Clemson's Department of Pesticide Regulation has an online lookup for licensed commercial companies. You can also call DPR at 864-646-2150, which is also the number for complaints.

City guides in South Carolina

Sources