Subterranean Termites in South Florida: Warning Signs, Season, and Protection

South Florida has two primary termite swarm seasons: (1) Eastern Subterranean Termites (Reticulitermes flavipes) — swarm February through May, typically in the afternoon during warm, sunny days following a rain event. This is the most common subterranean species across Broward and Palm Beach Counties. (2) Formosan Subterranean Termites (Coptotermes formosanus) — the most destructive species. Primary swarm season is April–June, with a secondary swarm in late July–August. Formosans swarm at dusk in large numbers — swarms of thousands of alates emerging at once. Formosan termites are particularly well-established in South Florida due to the subtropical climate and are responsible for an estimated $1 billion in annual US property damage. (3) Drywood Termites (Cryptotermes brevis and others) — swarm throughout the year in South Florida, with peaks in summer. Drywood termites don't require soil contact and infest wood directly. If you see swarmers inside your home at night around lights, Drywood termites are the likely source.

Termite damage and moisture damage can look similar — but there are key distinctions: (1) Moisture damage produces soft, discolored wood that may be crumbling or black with mold. Termite damage produces wood that is hollow inside but may look normal on the outside (subterranean) or has small kick-out holes in the surface with frass piles below (drywood). (2) Look for mud tubes — if the damage source is subterranean termites, you'll typically find mud tubes somewhere along the travel path from soil to the damaged wood. Moisture damage has no associated mud structure. (3) Live or dead insects — termite galleries contain workers, soldiers, and sometimes eggs. Moisture damage has no insects. (4) Pattern of damage — termites eat along the grain of soft wood; moisture damage affects wood more uniformly. (5) The most reliable determination is professional inspection — a licensed inspector with a moisture meter and termite detection experience can distinguish the two. South Florida's high moisture levels make water damage common, so accurate identification before treatment is critical.

Formosan subterranean termites (Coptotermes formosanus) are an invasive species from Asia that was introduced to the US through post-WWII military equipment transport. They're the most destructive termite species in the world for three reasons: (1) Colony size — Formosan colonies contain 1–10 million workers (vs. 100,000–300,000 for Eastern subterranean). A single Formosan colony can consume a pound of wood per day. (2) Aggressive foraging — Formosans can forage up to 300 feet from the colony, allowing a single colony to infest multiple adjacent structures. (3) Carton nests — unlike Eastern subterranean termites, Formosans can build moisture-retaining carton nests inside walls and structural voids that allow them to survive without returning to soil. This makes them harder to control. In Broward and Palm Beach Counties, Formosan termites are well-established — particularly in neighborhoods with older construction, mature tree stumps in yards, and railroad tie landscaping. Spring and early summer swarming events (typically at dusk following rain) are the visible indicator of Formosan presence.

Termite monitoring stations are in-ground devices installed around the perimeter of your home, spaced every 10–15 feet at soil level. Here's how they work: (1) Each station contains a wood cellulose interceptor that termites prefer over structural wood. Termites foraging through the soil encounter and feed on station interceptors before reaching your home's foundation. (2) At each inspection (quarterly or biannually), the interceptors are checked for termite activity. If termites are found feeding in a station, that station is loaded with a termiticide bait matrix (typically a chitin synthesis inhibitor like hexaflumuron or noviflumuron). (3) Worker termites carry the bait back to the colony and share it with the colony — the slow-acting mechanism allows transfer through the colony before mortality begins, achieving complete colony elimination. (4) Monitoring stations detect termite pressure before structural damage occurs. Unlike the traditional soil barrier (liquid termiticide), bait stations address colonies directly rather than just blocking one entry path. Annual monitoring with bait capability is the current industry standard for subterranean termite protection in South Florida.

Termite treatment costs in South Florida vary by species and method: (1) Subterranean termite monitoring stations — typically $500–$800 per year for initial installation and annual monitoring. This is an ongoing service, not a one-time treatment. (2) Soil liquid barrier (Termidor) — applied at construction or to existing structures; typically $700–$1,500 depending on linear footage. Effective against subterranean species but doesn't address Drywood termites. Requires reapplication every 5–10 years. (3) Drywood termite fumigation — whole-structure tent fumigation is the gold standard for Drywood termite elimination. Cost typically $1,500–$3,500 for average homes depending on size. Required when Drywood infestation is widespread through the structure. (4) Spot treatment — for localized Drywood termite infestations (single accessible area), spot injection or microwave treatment is less expensive than fumigation but limited to the treated area. The most cost-effective long-term approach in South Florida is annual monitoring stations — catching subterranean colonies early (before structural damage) avoids the far more expensive remediation of discovered damage.