Subterranean termites are arguably the most destructive species of termites, as they infest wood from underneath. In other words, their danger lies in that they remain hidden, and homeowners may not realize that there’s a termite infestation until their home is plagued with damaged wood.
So, in this article, we’ll cover all the subterranean termites facts you want to know.
What Are Subterranean Termites?
Subterranean termites live in corporate societies, which we call termite colonies. These colonies exist in the soil, hence their name. Numbers range from two to millions of these sub-termites living in a colony, sharing food, shelter, and so on. They also raise their young collectively.
However, we must understand the different types of members in a colony to answer questions like “what does a subterranean termite look like?” and “what does a subterranean termite do?”.
Most members of the colony are worker termites. These are cream-colored male and female insects with no wings. They’re around 1/8 inch long and sexually immature.
As the name implies, they put in the work, finding food for their nestmates, caring for the immatures and the eggs that are about to nest, making mud tubes and maintaining them, constructing galleries and other colonial structures, grooming, and feeding. Typically, homeowners spot these first thing in a subterranean termite infestation.
Aside from workers, some subterranean termites are soldiers. Consequently, their percentage in a termite colony varies among most subterranean termite species.
For instance, soldiers in Eastern subterranean termites comprise 1 to 2% of the colony. As for Formosan termite colonies, the soldier’s percentage is higher than it’s in an eastern subterranean termite colony; we’re talking 10%.
Like a subterranean termite worker, soldier termites are sexually immature males and females without wings. Moreover, their mandibles, or black jaws, enable them to do their job of defending the colony. Of course, workers might also play a part in that, but they don’t have the same fierce nature.
Finally, alates, reproductives, or swarmers are adult winged termites. Unlike other colony members, they have fully functional eyes. Moreover, they’re dark brown to black and have thick cuticles. This way, they can prevent water loss.
Also, termite swarmers become reproductive termites. To illustrate, they land somewhere, shed their wings, mate, and become kings or queens of new colonies.
Where Do Subterranean Termites Live?
If you’re wondering: “where are subterranean termites found?” you’ll find that these underground termites are widespread in California, inhabiting the soil and breeding in it. However, they also inhabit every state of the U.S except for Alaska.
Examples of subterranean termites’ likely colony locations are stumps, other dead wood in contact with the soil of a forest, structural lumber in a house, or a landscape. They might also be found infesting fallen trees. Moreover, some subterranean termites live in the desert areas in the southeast, but they aren’t our focus.
The most important types of subterranean termites are Reticulitermes, Coptotermes, and Heterotermes. Reticulitermes virginicus, also known as a dark south eastern subterranean termite colony, are arguably the most common and the most destructive termites found all over California. They live in the coast’s dunes, elevations of the mountain ranges, and deserts.
Coptotermes Formosanus, the Formosan subterranean termite, originated in China but is now found in California, near San Diego, to be specific.
What Do Subterranean Termite Species Eat?
Put simply; subterranean termites mainly feed on dead wood, wood scraps, and wood by-products. However, they also eat other items containing cellulose, including fiberboard, paper, and fabrics made from cotton or plant fibers. To elaborate, the digestive tracts of these wood species have protozoa, which can convert cellulose to functional food.
As for how they find their food, the termites typically track a moisture gradient or chemical to find food sources. They use abandoned tunnels dug by earthworms or ants or follow roots to find food.
But as mentioned, these termites live underneath the soil surface, so what happens if the wood doesn’t come in contact with the soil? Let’s say it’s 50 to 60 feet above the ground. In that case, they build the mud tunnels we’ve mentioned earlier to get to the wood. And they might use expansion joints in concrete slabs or utilities to infest a house.
Where Do Subterranean Termites Nest?
These termites tend to nest in the soil or somewhere close so that they can access it via termite tubes or tunnels in the wood. After all, they need the moisture found in the soil to avoid desiccation. Not to mention, soil protects them against predators. Also, Formosan termites use it to build carton nests.
Life Cycle Of Subterranean Termites
Subterranean termites self-perpetuate. So, there’ll be a few swarming termites in a big colony that leave the nest. They fly in swarms but don’t go further than 100 meters from their termite colony and find a mate. Then, they disperse to find new nest sites and begin new colonies.
Also, the time for these flights differs from one species to another. To exemplify, Reticulitermes do so in the afternoons of spring or fall after the rain clears up. But Hetertermes fly to mate in the late afternoons or early evenings of July, August, and September.
Finally, Coptotermes formosanus flies in the late evenings. However, it’s worth noting that not all of these trips are successful. Most reproductive termites don’t make it out alive because they encounter ants, insects, birds, and lizards that prey on them.
But the pairs that do make it create an underground chamber, which they close off. After they’ve mated, the female lays eggs. Then, the king and queen feed their young ones predigested food until they’re old enough to feed themselves. Eventually, the colony produces workers tasked with providing the colony members.
As for their lifespan, workers may live a year or several years, but kings and queens can live up to a decade or even more.
How Do You Identify Subterranean Termite Colonies?
Since they operate underground, these are some signs to identify subterranean termite infestations.
As we’ve mentioned, termites build mud tubes to protect themselves using soil, excrement, and saliva. These mud shelter tubes connect the nest in the soil to the targeted wood. And sometimes, they build aerial nests, constructing tubes with no soil.
Additionally, mud tubes usually have an earthlike appearance and are flattened. Also, they can have the thickness of a pencil, but they might be several inches wide in a more severe subterranean termite infestation. So, inspecting your house once a year for tubes is advisable.
Also, if your house has crawl spaces, check it’s inside and outside. Other possible locations for a termite infestation are cracks in concrete floors and foundation, empty spots in concrete block foundations, behind baseboards, between the sill plate and foundation walls, behind obstructions, and spots where pipes and utilities go through slabs.
It’s worth noting that the termite damage is below the surface of the wood, so you may not see it. But a good way of checking for wood decay is tapping the wood with the screwdriver’s handle every few inches.
Notice how the wood sounds; if it sounds hollow, it’s damaged. That tap might go as far as to puncture the thin wood, exposing the gallery. Needless to say, finding live termites inside is all the confirmation you need. Wood structures are also sometimes darkened or blistered.
Moreover, like drywood termites, these termites follow the grain of the wood when feeding. They don’t feed on the hard summerwood because it’s difficult to digest. Instead, they attack the soft springwood, which gives the damaged wood a layered appearance. Also, you’ll find mud and soil in the tunnels subterranean termites create.
And unlike drywood termites and other species, they don’t extract wood pellets or particles from the decayed wood. However, these termites construct tunnels with them, creating hollow, enclosed ones.
We’ve talked a bit about how a subterranean termite looks, but let’s see which one you’re likely to see and where. Winged reproductives or termite swarmers are dark brown to black insects. They’re drawn to light, meaning that they go to light fixtures, window sills, doors, and vents. So, you’ll find the termite wings they shed on window sills and floors; you might even find a spider web.
Unfortunately, you may have hired subterranean termite control and still find swarmers days or weeks after. That means the colony has produced them in those testing conditions, which is a common practice for it. This way, the swarmers can fly, find mates, and start a new colony.
Tip: If you’re struggling to differentiate between swarmers and flying ants, a subterranean termite has a straight antenna, thick waist, and equal-sized wings.
Not only can a subterranean termite feed on wood, but it can also damage insulation systems. To elaborate, some types of insulation feature a paper cover, which termites eat. And they can easily pass through insulation due to its softness. Nonetheless, they don’t feed on the insulation itself because it holds no nutritional value to them, but they still damage it and undermine its thermal resistance.
So, how can you detect insulation damage? Inexplicable surges in energy bills typically accompany the loss of insulation properties.
How Can You Tell The Difference Between Subterranean Termites And Other Species?
We’ll focus on two other termite types, so here are the main differences:
Drywood termites differ from subterranean ones in that they use cellulose-based materials, including wooden trim, waste lumber, and siding, to make their nests. Also, they don’t need moisture from the soil, as they get it from wood. Finally, these insects feed on the wood in furniture, books, and floors.
Dampwood termites colonies exist in wet wood and even decayed wood. They prefer to nest in wood structures that are wet or in contact with soil. And signs of an infestation by dampwood termites are leaky pipes and moisture problems.
Are Subterranean Termites Dangerous?
As we’ve said, the danger of these termites can easily continue undetected. Subterranean termites feed on books, paper products, wood, cellulose-based products, and other plant-based goods. Furthermore, their numbers can multiply quickly. If a colony has more than one egg-laying female, nests can grow drastically, producing hundreds and even thousands of members.
Now, a subterranean termite infestation can go on for years before it’s detected, and the damage caused can cost homeowners billions of dollars. Even worse, a subterranean termite problem can cause a building to collapse, which means drastic losses for homeowners.
How Do You Prevent A Subterranean Termite Infestation?
We’ve discussed how inspecting a house every year is a good idea, but what more is there to do? To prevent termite infestations, precautions start even before the construction of a building begins, and that means you should:
- Get rid of roots, wood, stumps, foam boards, grade stakes, and so on. This way, any already existing colonies aren’t a risk.
- Avoid any contact between the soil or fill and building woodwork. So, make sure that any exterior woodwork is at least 6 inches from the ground and that crawl space beams are no less than 18 inches above the ground.
- Commercially pressure-treat any wood that contacts the soil, such as poles, fence posts, and general foundation structures.
- Install proper ventilation openings in foundations so that there are no dead air pockets. Instead, the pockets should allow frequent air movement, deeming the ground dry and uninhabitable for termites. Accordingly, the openings shouldn’t be smaller than 2 square feet at least every 25 linear feet of the outside foundation wall.
- Place landscape plants and irrigation over 2 feet away from the foundation.
How Do You Get Rid Of Subterranean Termites?
A licensed pest control professional will conduct an inspection before treatment, and you should hire one every several years.
Toxic termite baits are paper, cardboard, or other objects that termites eat, but they contain a slow-acting insecticide. Of course, that makes it an effective control method, but homeowners must give it time. Thanks to insect growth regulators (IGRs), this method is effective on termites, but its toxicity is very low to humans and pets.
There are other non-toxic ones as well. You’ll find options for homeowners to use and other more effective ones for professionals.
Either way, the goal of termite baiting systems is to cut down the number of subterranean termites closing in on the wood structure by either killing the termites or diverting their foraging activity.
As a rule of thumb, they have a better chance if they’re installed deep below the ground. Nonetheless, termite baits may need to be above ground if the termite activity is detected there, and the control method is more effective in that case than it usually is underground. Also, termite control professionals use one of three methods:
- Monitoring Station: Such a station detects active subterranean termite colonies. After detection, a baiting station replaces the monitoring station.
- Placing Baits: Some pest management professionals don’t install monitoring stations but place the baits right away.
- Inspection: This is where professionals inspect a site for mud tubes, soil and wood portions damage, and other signs we’ve mentioned. Then, they put the bait stations in the places with visible infestations.
Conventional liquid termiticides, also known as termite barriers, are a standard termite control method. And professionals inject the soil or drench it in insecticides, targeting nests via mud shelter tubes.
However, note that effective products are strictly for professional use. That’s because specialists know where to inject the soil with insecticides safely. They consider the soil type, application techniques, and weather conditions before proceeding with subterranean termite control.
Otherwise, homeowners might apply insecticides to the wrong spot. Accordingly, they can damage heat pipes, plumbing, and sewage or contaminate heating ducts, groundwater, or surface water.
As for professionals, they might dig narrow trenches alongside the interior and exterior of foundation walls and around chimney bases and piers. Then, they mix the insecticide with water as recommended on its label, apply it, and mix it with the soil.
Not long ago, these insecticides featured repellent or nonrepellent ingredients.
Repellant insecticides, mainly pyrethroids, would repel a termite without killing it. Unfortunately, repellent insecticides have taken a back seat to their counterparts due to their ineffectiveness.
Nonrepellent chemicals contain fipronil, chlorantraniliprole, and imidacloprid. They’re highly toxic to subterranean termites but not very harmful to humans and other mammals.
Still, we should establish that this insecticide won’t stop a subterranean termite from attacking wood and other wood sources. They’ll live up to 90 days before the insecticide is in full effect, which is sufficient time for the termite poison to spread from any infected subterranean termite to other termites in the colony.
As a result, their population will decline, and the insecticides will kill most or all of the subterranean termites in the colony.
All in all, we hope these facts about subterranean termites have been helpful. You can use our tips to identify the different types of subterranean termites: workers, soldiers, and reproductives. You should also be able to differentiate between a subterranean termite and other termite species. Moreover, you have other signs to note, such as infested wood, fallen wings, and so on.
Nevertheless, the most effective methods of termite control are pre-construction procedures that prevent termite entry. In addition, they ensure that no soil and wood contact occurs, as that makes a good potential spot for a colony and protects termites. Still, professionals use insecticides and termite baits to decline and kill colonies. As for homeowners, they can use some insecticide types.
Either way, the secret is patience and perseverance because there are no quick fixes for a termite infestation, and it might be months before the termite control method is in effect.
- ENY-210/IG097: Subterranean Termites (ufl.edu)
- Subterranean and Other Termites Management Guidelines–UC IPM (ucanr.edu)
- Subterranean Termites – How To Kill and Get Rid of Subterranean Termites (epestsupply.com)
- Subterranean Termites (orkin.com)
- Subterranean Termites: Damage, Prevention, & Control: NPMA (pestworld.org)