What Are Formosan Termites? A South Florida Homeowner's Guide

Formosan termites (Coptotermes formosanus) are an invasive species of subterranean termite, native to Taiwan and southern China, that builds some of the largest and most destructive colonies of any termite. A single mature colony can contain several million termites, and UF/IFAS lists the species among the most damaging termites in the world.

They are sometimes called “super termites,” and in South Florida that reputation is earned. This guide covers where Formosan termites came from, how to recognize every caste, when they swarm, how they live and what they mean for your home.

Where Formosan Termites Came From

The name comes from Formosa, the historical name of Taiwan. According to UF/IFAS, the species is native to Taiwan and southern China and spread around the world mostly through human transport, including maritime shipping and global trade. It was first described in Hawaii in the late 1800s, and early introductions on the US mainland were recorded in New Orleans, Charleston and Hallandale, Florida.

Today, Formosan termites are found in Hawaii, across the southeastern states north to Virginia and inland to Tennessee, and in southern California. In Florida, they occur statewide but are concentrated in densely populated urban areas.

Still Spreading in Florida

A 2026 University of Florida study based on termite records from 1990 to 2025 found Formosan termites established in most of Florida’s coastal counties and most large urban centers, and it gives them a high likelihood of being detected statewide before 2050. The same research notes that a 2016 projection, that about half of the structures in urban South Florida could be at risk from Formosan or Asian subterranean termites by around 2040, remains on track.

How to Identify Formosan Termites

A Formosan colony has three main castes. You are most likely to see swarmers, but soldiers are the best way for an expert to confirm the species.

Workers

Workers are about 3 to 4 mm long, wingless and white to cream-colored, with short, darkened mandibles. They are the caste that eats wood and causes the damage. You usually see them only when a mud tube or damaged board is broken open.

Soldiers

Soldiers are about 4 to 5 mm long, with a white body, a brownish-orange, teardrop-shaped head and long, dark, curved mandibles. They have an opening on the front of the head, called a fontanelle, that releases a white, glue-like defensive fluid when they are disturbed. If you see a drop of milky liquid when you poke a mud tube, you are probably looking at Coptotermes.

Formosan colonies also carry far more soldiers than native termites, which helps inspectors tell them apart:

Swarmers (Alates)

Winged reproductives are about 12 to 15 mm long, orange to light amber-brown and darker than the other castes. They have four wings of equal length, with two darkened veins along the top edge, and their bodies and wings are covered in fine hairs. They shed those wings soon after landing.

Native-species figures come from UF/IFAS. Compare both on our Formosan subterranean termite page.

When Formosan Termites Swarm

In Florida, Formosan termites swarm from early April to late June, peaking in May, shortly after sunset. UF/IFAS notes that swarms can include tens of thousands of termites, that swarmers are strongly attracted to lights and that swarms can happen indoors in infested buildings.

That evening timing is a useful clue. Winged insects crowding a porch light on a warm May night, or covering a windowsill the next morning with shed wings, are a reason to collect a sample. For the full calendar of every species, see when termite swarming season is, and to rule out ants, use our guide to termites vs. flying ants.

How a Formosan Colony Lives

Huge, Long-Lived Colonies

UF/IFAS reports that Formosan colonies take about 5 to 8 years to mature and can grow to several million termites. Field studies have documented foraging distances of up to about 100 meters, which means a colony under a neighbor’s yard or a nearby tree can reach your house. Mississippi State University Extension adds that Formosan termites readily attack cypress as well as pine and hardwoods, unlike native subterranean termites.

Mud Tubes and Carton Nests

Like other subterranean termites, Formosans reach wood through mud tubes made of soil and saliva, which protect them from predators and from drying out. What sets Coptotermes apart is carton: a mix of soil, chewed wood, saliva and feces that workers pack into voids. With a steady moisture source, such as a roof leak or a plumbing drip, part of a colony can nest inside a wall without returning to the soil.

Trees as Hidden Nests

Formosan termites hollow out the dead wood at the center of living trees. The tree may not die, but UF/IFAS warns it can weaken and become more likely to collapse in high winds, a real concern in hurricane season. Infested trees near a home are both a storm hazard and a source of termites.

Hybrids With Asian Subterranean Termites

In urban South Florida, Formosan and Asian subterranean termites live in the same neighborhoods and both swarm in spring. In 2025, UF/IFAS scientists confirmed that hybrid colonies of the two species are established in South Florida, after finding one in a tree in a Fort Lauderdale park. Hybrid swarms have been recorded every year since 2021. The researchers say the economic impact is still unknown.

Why Formosan Termites Are So Destructive

UF/IFAS estimates that Formosan subterranean termites alone likely cause over $4 billion in damage a year in the United States, and the species has been listed among the 100 worst invasive species. Their impact comes from a combination of traits:

• Colony size: millions of workers eat far more wood than a native colony.
• Reach: long foraging distances let one colony attack several structures.
• Hidden nests: carton nests in walls keep damage out of sight.
• Tree infestations: hollowed trees weaken and can fall onto homes.

For a deeper look at the risks, read why Formosan termites are so concerning, and for the cracks, joints and gaps they use to get inside, see how Formosan termites enter buildings.

How Formosan Termites Are Controlled

UF/IFAS states that over-the-counter products are unlikely to be effective and that Formosan control requires professional services. The two proven methods are:

• Baits: stations in the ground, or above ground at active foraging sites, hold a bait that workers share with the colony. The termites die as they fail to molt, which UF/IFAS says can eliminate a colony in about 3 months.
• Liquid termiticides: soil treatments around the foundation, or injections into cracks and voids, keep termites out of the treated zone, although they may not eliminate the colony itself.

Tenting is not a solution for subterranean termites, because the colony lives outside the structure. Prevention still matters: our guide on how to prevent Formosan termite infestations covers moisture, wood contact and tree care.

Toro’s termite control service treats Formosan, Asian and eastern subterranean termites with the Sentricon baiting system, installed in the soil around the property with no drilling into the slab and designed to eliminate the colony, including the queen. Every job starts with a free inspection by a technician trained at the TORO Institute with Toro’s on-staff entomologists, and the stations stay in place for year-round protection.

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Frequently Asked Questions

Educational content. This article is for general information about pests in South Florida and is not medical, legal or professional advice. If you have a bite, sting or allergic reaction, contact your doctor; in an emergency, call 911. Pest problems vary from home to home, so a licensed professional should inspect before treatment. When using any pesticide, always read and follow the product label.

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