Formosan Termites: A Comprehensive Guide to Identification and Control

Formosan termites are a subterranean species known for their aggressive and destructive nature. Often referred to as “super termites,” they are considered one of the most voracious and devious among over 2,000 termite species. These termites can chew through wood, flooring, and even wallpaper without being detected, making them a significant threat to homeowners in regions where they are prevalent.

Originally from southern China, Formosan termites have spread to numerous countries, including Taiwan, Japan, South Africa, Sri Lanka, and the United States. They are primarily found in the US in the southern states, such as Florida, Alabama, Georgia, Louisiana, Mississippi, and Texas. These invasive termites continue to cause significant damage to properties across their inhabiting regions.

The Formosan termite species have three distinct castes: alates (reproductive), soldiers, and workers. Each caste plays a specific role in maintaining the termite colony and contributing to its growth. Due to their large colony sizes and voracious appetite for wood, Formosan termites can cause extensive damage much faster than other termite species, making their presence a growing concern for homeowners and pest control professionals.

Formosan Termite Identification

Physical Characteristics

Formosan termites are a species of subterranean termites known for their voracious appetite and large colonies. They are typically light brown to yellowish-white in color, with creamy white bodies and small hairs. One key feature for identifying Formosan termites is their straight antennae, which may droop slightly.

Castes

Formosan termites exhibit a clear caste system within their colonies, consisting of alates (reproductive termites), soldiers, and workers. Each caste has distinct physical characteristics that aid in identification:

• Alates: Also called swarmers, alates are the reproductive members of the Formosan termite colony. They are relatively larger than other castes, with elongated bodies, measuring approximately 12-15 mm long. Alates have two pairs of wings that are roughly equal in length, an important identifier for termite swarms. These wings eventually detach once they’ve found a suitable location to start a new colony.
• Soldiers: Formosan termite soldiers defend the colony from potential threats. They have distinct, enlarged, yellow-brown heads with strong, curved mandibles to help combat intruders. Soldiers measure about 6-7 mm in size, making them easily distinguishable from workers.
• Workers: Workers are responsible for foraging food, maintaining the colony, and caring for alates and soldiers. They are the smallest caste, measuring only around 3-4 mm in size. Workers have soft, pale, segmented bodies and are generally less distinguishable from other termite species.

To correctly identify Formosan termites in your home or surroundings, it is important to note their physical characteristics across different castes while paying attention to their movement patterns and typical habitats. By recognizing their unique traits, you can take appropriate measures to control and prevent potential infestations.

Distribution and Habitat

Formosan termites, known as the most aggressive and voracious termite species, thrive in warm environments, residing in underground colonies and feasting on wood and other cellulose-based materials. Moisture-rich soil and a constant supply of timber are essential for their habitat.

Origins

Formosan termites originated in Southern China and Taiwan. They are believed to have spread throughout Asia before reaching other parts of the world. These termites have adapted to various environments and expanded their distribution, causing significant infrastructural damage in several regions.

United States

Formosan termites have spread across several states in the United States, particularly in the southern region. They have been documented in states like:

• Hawaii: The species was first identified in the US on the Hawaiian Islands, where it has continued to thrive in the ideal warm and moist conditions.
• Florida: Formosan termites have established a significant presence in urban southeastern Florida, particularly in the coastal areas of Dade, Broward, and Palm Beach Counties.
• Texas and California: The termite species is also prevalent in Texas and California, spreading through urban regions and causing considerable property damage.
• Other Southern States: Formosan termites have been detected in Alabama, Georgia, Mississippi, South Carolina, and Tennessee.

These termites are not limited to the southern states but instead continue to spread throughout the US due to their aggressive nature and ability to adapt to various environments.

International Spread

Besides their origin in Southern China and Taiwan, Formosan termites have expanded their reach internationally, causing damage to structures and wood-based materials in their path. They have been reported in Sri Lanka and Midway Island. Their distribution is wider than these regions, though, as they continue establishing colonies and spreading to other parts of the world.

Formosan termites have become a global threat due to their voracious appetite for wood and ability to adapt to new environments, which has led to ongoing efforts to implement control measures to protect vital infrastructure and prevent further property damage.

Infestation and Damage

Signs of Infestation

Formosan termites are a particularly aggressive and destructive species of subterranean termites. When infesting a home or property, these termites create mud tubes to forage for food and avoid exposure to light. Mud tubes can be found near a building’s foundation, crawlspaces, and wood structures connected to the ground. One of the most apparent signs of a Formosan termite infestation is the presence of damaged wood that sounds hollow when tapped. The wood often appears to have been eaten away along the grain pattern, which can lead to severe structural damage if left untreated 

Structural Damage

The damage caused by Formosan subterranean termites can be extensive, as they are capable of bypassing treated wood to infest untreated wood in structures 2. This can lead to the weakening of wooden beams, floors, walls, and the structural foundation of a building, putting homeowners at risk of significant financial loss. Furthermore, these termites can construct cartons to retain moisture, allowing them to establish nests within structures and expedite the rate of damage.

Impact on Trees and Plants

While their primary target is wood, Formosan termites also pose a threat to trees and plants because they are attracted to cellulose material. This attraction can result in extensive damage to trees, reducing their structural integrity and potentially causing them to collapse. Additionally, the infestation can exacerbate existing tree diseases and negatively impact overall plant health. Homeowners and property managers must remain vigilant in identifying and addressing Formosan termite infestations to protect their trees, plants, and buildings from extensive damage.

Biology and Behavior

Colony Structure

Formosan termites are a type of subterranean termite known for their destructive nature and ability to cause severe damage to buildings and wood structures. Their colonies are highly organized, with a caste system consisting of a king, queen, soldiers, workers, and reproductives. The king and queen are the primary reproductives, producing eggs that develop into various castes within the colony. Soldiers, characterized by their large heads and strong mandibles, serve to protect the colony from intruders, while workers perform all the necessary tasks to maintain the colony, such as foraging for food, feeding other castes, caring for eggs, and building carton nests.

Swarming

Swarming, a key aspect of Formosan termite behavior, occurs when winged reproductives called alates emerge from the colony to seek out new locations for establishing new colonies. This typically happens during warm, humid evenings with still air, as they are attracted to lights. The alates will swarm, lose their wings, and pair up to form a new king and queen reproductive pair for the new colony.

Feeding Habits

Formosan termites are primarily wood-feeders, consuming wood and other cellulose materials. Although subterranean in nature, they can build shelter tubes and aerial nest structures called carton nests by using a combination of faecal matter, saliva, and wood particles. These carton nests allow them to access food above ground without returning to the soil, as well as retain moisture essential for their survival. They are known to attack a wide range of plant species, exhibiting a preference for certain types, such as citrus, wild cherry, cherry laurel, sweet gum, cedar, willow, wax myrtle, Chinese elm, and white oak . Being subterranean termites, they establish their foraging areas underground, utilizing networks of tunnels to locate and access food and water source.

Prevention and Control

Inspection and Detection

Formosan termites, also known as Coptotermes formosanus, are invasive termites that cause significant damage in the United States. These termites can be found in various states, including Louisiana. If you want to protect your home, make sure to conduct regular inspections and detect their presence early.

A thorough inspection should be carried out by a pest management professional, as they have the expertise to identify signs of termite activity, such as swarming, termite droppings, and damages to the foundation or wooden structures. Swarming tends to happen in April, and the University of Florida recommends observing for swarmers with distinct, rectangular heads.

Treatment Methods

Once Formosan termites have been detected, several treatment options can be employed by a pest management professional. Some of these include:

• Insecticide: Applying termiticides to the soil surrounding the foundation and to wooden structures can help control the termite population by killing or repelling the termites.
• Baiting Stations: These are placed around the property to lure termites away from the buildings. The bait, which is often laced with slow-acting insecticide, is taken back to the colony, eventually eliminating it.
• Fumigation: As a more extreme measure, the entire structure can be fumigated to kill existing termite colonies and prevent new infestations.

It is essential to consult with a knowledgeable professional to determine the most effective treatment method for your specific situation.

Preventive Measures

To prevent Formosan termite infestations, consider implementing the following preventive measures:

• Divert Water: Redirect water away from your home’s foundation, using properly functioning downspouts, gutters, and splash blocks, to avoid giving termites easy access to your structure.
• Concrete Foundation: During construction, use a concrete foundation and leave a ventilation space between the soil and wood, as this makes the structure less attractive to termites.
• Store Firewood Properly: Formosan termites thrive on firewood. Keep firewood at least 20 feet away from the home, and avoid stacking it against the house.
• Education: Stay informed on Formosan termite prevention and control strategies, such as those provided by the Department of Agriculture.

Adhering to these preventive measures ensures that you minimize the risk of Formosan termite infestations and maintain the integrity of your property.

Frequently Asked Questions

How do they enter the house?

Formosan termites enter homes through wood that touches the soil, or by traveling from the ground to infested wood via mud tubes they create. Cracks in the foundation or around windows and doors can also provide entry points for these termites. They are attracted to moisture, so any damp areas in your house are also at risk of termite invasion.

What are the signs of an infestation?

Signs of a Formosan termite infestation include the presence of shelter tubes made of mud, which they build for protection while travelling, sightings of winged swarmers during their mating season, and areas with damaged or hollowed-out wood. Additionally, piles of discarded wings near windows or doors can indicate a recent termite swarming event. Bubbling or distorted paint, mud tubes near the foundation, and sagging floors are also possible indicators of an infestation. 

How to distinguish them from subterranean termites?

Formosan termites are a type of subterranean termite. However, they can be distinguished from other subterranean termites by the size and color of their caste members. Formosan termite soldiers have a more rounded and orange-colored head, while other subterranean termite soldiers have narrower and darker ones. Additionally, Formosan termites are more aggressive and fast-acting compared to other subterranean termites. Source

What preventive measures can be taken?

To prevent Formosan termite infestations, start by minimizing wood-to-soil contact around your home. Remove any wooden debris from around the foundation, maintain a barrier between mulch and the house, and avoid using wood as ground cover in garden beds. Sealing gaps and cracks in the foundation is also essential to restrict termite access. Properly ventilating crawl spaces and other areas, as well as maintaining good drainage and gutters, can reduce excess moisture, which attracts termites.

Where do they typically reside?

Formosan termites primarily reside in large underground colonies, where they can cause extensive damage to wood and other organic materials. They can also establish secondary nests above ground, often in damp or moist areas, such as attics, basements, crawl spaces, or even within walls. Source

How severe is the damage they cause?

Formosan termites are highly destructive and can cause significant structural damage in a relatively short time. They are regarded as the most aggressive and voracious termite species due to their large colony size and ability to consume vast amounts of cellulose material. The cost of repairing Formosan termite damage is often substantial and can lead to structural failure if not addressed quickly.