At first the 15-foot by 4-foot plexiglass case looks like a massive piece of art — an abstract of a river delta or the veins of a leaf. But then you see tiny pale things scuttling, moving their way like white blood cells along every vein.
They’re termites, “2.5 million of them,” said Thomas Chouvenc with pride as he sits above what he calls an “arena.” He’s an urban entomologist at the University of Florida’s research center in Davie, and these are his babies. His lab houses some 25 million termites of various species in a quest to figure out how to stop them.
“Termite swarm season is almost upon us,” he says. “Things are about to get very busy.”
Around South Florida you’ll soon see clouds of termites bobbing around street and porch lights. And you’ll certainly see the ensuing tenting operations, as property owners fumigate.
But Chouvenc warns that those tents only deal with the tamest of the three destructive termite species in Florida, the West Indian drywood termite.
In fact, the other two species are invasive, and can spread much faster and are much more destructive. They’ve been here since the 1990s, and are spreading, affecting more and more neighborhoods around South Florida and moving north. And it’s not just homes that are under threat. The cherished tree canopies of Fort Lauderdale also are being eaten away.
Both species — the Asian subterranean termite and Formosan subterranean termite — are voracious, and both build colonies underground or within trees.
Their extraordinary colonies function like a complex matrix of veins, and can reach exploratory tendrils out 100 yards in any direction to find the food they need. If those veins encounter your house, the termites can build a bridge out of their poop to climb up and find their way in.
It’s all nearly invisible. But each of the three destructive species swarm at different times in spring and summer, giving themselves away.
Asian termites swarm first, in March. The Formosan termites swarm from late April to early May and the drywood termites swarm from early May to the end of June.
The damage
“Drywood termites can do damage over time, but they’re stuck in a single piece of wood,” said Chouvenc.
For instance, they can live in a beam in your attic, but they can only damage that beam, until the colony grows large enough to create a swarm, which takes five years.
“But with subterranean termites, any sign you see is the tip of the iceberg,” said Chouvenc, who is a Johnny Appleseed of sorts, spreading the gospel on the threat of invasives.
Tenting doesn’t work, because the main colony is in the soil or a tree outside the house. Fumigation will only kill the termite inside the house, and others will soon reinfest.
Millions of subterranean termites live in a colony, and a colony can consume 900 pounds of wood in a year. Their veins allow them to find and destroy more wood more quickly than drywood termites.
In other words, termite treatment changes completely by species.
“When we go out and do a treatment we’ve gotta really identify the difference between the subterranean termite we’re dealing with,” said Eric Hoffer, whose Hoffer Pest Solutions has been in operation since 1975, and covers Palm Beach, Broward and Miami-Dade counties, and agrees the newcomers are more destructive.
“We are entering a new norm in terms of potential termite damage because the termite problem is changing in Florida,” said Chouvenc. “Florida’s year-round, warm climate has allowed several invasive termite species to thrive and cause structural damage to our homes … and impact on our urban tree canopy.”
How to tell if termites threaten your home
Chouvenc and his peers at the University of Florida have developed an interactive termite distribution map so you can see which species of termite is in your area. You can view several species, or just one, then zoom into your neighborhood to get a sense of sighting densities and how long the species has been there.
Researchers pulled the data from a 30-year collaboration with exterminators. Chouvenc clarifies that the map is biased, in that it only shows where people notice termites, so there are inherently more sightings where more people live.
To suss out subterranean termites on your property, look for mud tubes coming out from the ground to the foundation of your house.
They look like a thick straw covered in brown sand, and act as elevated tunnels that connect the colony tentacles with new food sources, and protect the termites inside from sun and predators. The termites construct mud with soil and termite poop.
Also look for mud tubes to follow the grain of the wood along tree trunks and branches, and be sure to inspect beams when renovating.
Another sign of subterranean termites is unusual moisture marks in your house — it might not be a roof leak, it could be from termites carrying moisture.
With drywood termites, you’ll see little coffee-ground-like droppings throughout the house.
“If a termite flies into your house, it doesn’t mean your house is infested,” said Chouvenc, “it means you live in an area that’s at risk.”
If you see swarms at your porch light, it’s not necessarily a big deal, he said. “That’s not the problem. The problem is the colony that’s been chewing on the tree next door. A swarm is smoke. Where’s the fire?”
Chouvenc said that 99.9% of flying termites will die. “If they fly into your house, they’re dead. You don’t have to worry. If they are from your house, that’s a different story. The fire is in your house.”
It’s crucial, but difficult, to identify species. The University of Florida has a free identification service. If you find termites, put them in a zip-top bag and mail them in, or drop the bag off at their extension campus in Davie (Termite ID Team, Ft Lauderdale Research and Education Center, University of Florida IFAS, 3205 College Ave, Davie).
There are some key areas to find them. Termites will often drop dead beneath the lights to which they swarm. You can also check nearby spider webs. Pluck out dead termites, “but don’t hurt the spider,” said Chouvenc. He also advises checking the pool. “You’ll have a coating of termites on the pool surface. Scoop them up and send them in.”
Save trees, save shade, save homes
Trees can serve as a base for the main colony of subterranean termites, which can eventually reach your house. But the termites can also destroy beloved tree canopies.
The insects usually establish a colony at the base of a tree. If you cut the tree open in five years you’re likely to find the core 60% of the trunk be hollowed out with a rough, dry sponge-like material in its place. That sponge is called carton, and is made of termite poop.
“They use their poop to 3-D print their own architecture inside,” said Chouvenc. Those pathways help them reach new foraging areas in the tree, or your house. The tree is essentially a shell. “That tree is no longer able to survive a hurricane,” said Chouvenc.
He suggests inspecting trees for mud tubes on the exterior or carton material while pruning.
“All of these areas with beautiful canopy — Wilton Manors, Riverside, Riverland, Shady Banks — they’re getting hammered right now with Asian subterranean termites. If homeowners do tree inspection and can notify their pest control, you can save a tree.”
Should you cut down a tree if you see a bit of carton material? “Absolutely not,” Chouvenc said. “Fort Lauderdale has a mandate to keep (the city) green. Call pest control. Eliminate the colony. Save a tree.”
History of an invasion
The more aggressive subterranean termite invasion started after World War II, when Asian and Formosan termites came to the U.S. in military equipment returning from the Pacific theater. When the boats docked in New Orleans, the termites swarmed and found plenty of food and a warm enough climate.
Currently, Formosan termites, a subtropical species that originally came from Taiwan, Hong Kong and South China, range from Texas, through Louisiana to the Carolinas.
The tropical Asian termites came from Southeast Asia and die in cooler weather, and are limited to South and Central Florida.
Even the West Indian drywood termite, the one that prompts tenting, is technically invasive. The came here from Peru and Chile a few hundred years ago, Chouvenc said.
The native eastern subterranean termite also is a pest, and ranges from Toronto to Florida Keys. Most of the other species are native and no threat to your home. They just chew on dead branches.
Chouvenc said boats in Fort Lauderdale face subterranean termite infestations, and are vectors for spread. “I would argue that Fort Lauderdale is the prime exporter of invasive termites, because boats get infested here, because the species are fully established.”
Researchers have found the bugs in privately owned boats, often with plenty of beautiful woodwork to consume. When the boats docks somewhere else in the world, the bugs swarm and start new colonies.
Back in the 1990s, Hoffer said that termite services mostly dealt with drywood termites or less destructive native subterranean termites.
“We have noticed a difference in how destructive the species are,” he said. “The (native) eastern subterranean termite is not as destructive as the Formosan and Asian subterranean termites we’re out here battling.”
Methods of control
Tenting only applies to drywood termites. The subterranean species require baits that exterminators stick into the ground. The baits play on their biology — the tentacles of the colony will eventually encounter bait sticks as the insects search for food.
When the worker termites eat the bait, they take it back to the core of the colony.
If 5% of workers chew on the bait, they’ll share it with the whole colony within a week. The deaths will be staggered.
Within 2.5 months, the colony should be exterminated. Pest control workers can use above-ground bait stations for trees.
There’s also liquid treatments, placed around a structure, that kill termites that contact it.
This creates a “death zone,” Chouvenc said, and termites that encounter it will turn back. Liquids don’t eliminate colonies, but they temporarily protect structures.
Hoff feels like the technology has caught up with the bugs.
“While there’s been additional termite species that have been introduced, the technology that we’re using has also advanced,” he said. “I could not imagine trying to treat subterranean Formosan termites back in the ’80s, when all we had was repellant, insecticides and doing sub-slab treatment.”
The future and climate change
Florida’s warming climate benefits the invasives.
“We expect species that like warm climates to slowly move northward in the next half century,” Chouvenc said.
Though Formosans already range into the South, the Asian subterranean termite — which was first detected in 1996 in Miami, and has been hemmed in by cool winter nights — is expanding its range north.
“If you look at the (U.S.Department of Agriculture) tropical line, 20 years ago it was between Naples and Palm Beach. That line has now moved to Tampa and Melbourne.”
As if on cue, he and his team detected Asian subterranean termites in Tampa and Melbourne last year.
He said Orlando is next.
