Following significant swarms of Formosan termites in the New Orleans area, here is some basic information on the pesky critters:
Where are you from?
They are not native to Formosa but are native to mainland China, but were given the imprecise nickname by a Japanese scientist who “discovered” them on the island of Formosa, now Taiwan, at the turn of the 20th century.
This Formosan termite is a soldier in a well-organized army of millions. When they band together, Formosans make a perfect eating machine, wre…
How did you come here?
The termites infested packing crate wood used to ship equipment to the United States towards the end of World War II. Some of the boxes were buried at Camp Leroy Johnson, across from the industrial canal from Lakefront Airport on the shores of Lake Pontchartrain. Infested packaging material also ended up in the Algiers naval station. In the Lake Charles area, wooden landing craft returning from the Far East after the war were also infested with Formosans. Since then, the insects have expanded their range through their own swarm or through humans moving infested wood to new locations.
Close up of Formosa termites. The large white insect above is a secondary queen. Below, with dark brown tongs, is a soldier. The other one…
What different forms are there?
Baby Formosans spawned by the queen and king of a nest grow into one of several castes:
- White colored workers that gather food and build nests.
- Soldiers with tan bodies and tan heads and pincers that protect colonies from invading insects, including invasive fire ants.
- Alates, the winged, reproductive version we see swarming at sunset.
On Monday, May 9, 2006, Formosan termite workers were hard at work on a dead root of a pine tree damaged by Katrina. (file…
How are new nests formed?
The reproductive Formosan termites can only fly about 300 meters and use the moon’s light to fly as far away from their original nest as possible. That is why they are attracted to street lamps and lights in houses and other buildings. So turn off your outside lights and close your curtains when they swarm.
It only takes a single male and female to build a nest. They fly until their wings fall off, find a mate, and then seek shelter, preferably near or inside a source of cellulose such as a tree or wall with wooden supports and close to a source of moisture. The pair becomes king and queen, and within five years the queen begins producing caste members for the new nest.
Formosan termites swarm from the lights of a soccer field in May 2020. (Archive photo by David Grunfeld)
When do they swarm?
Formosans flock from April to June, flying at dusk on days that usually follow heavy rains, when temperatures are near 80 degrees and winds are less than 8 km/h. In the US, termites appear to have adjusted to having a large swarm on or around May 10, often coinciding with Mother’s Day dinner.
Formosan termites forage for food in the New Orleans city mosquito during the first Bug Fest on Saturday, May 12, 2018 in a display arena…
Why are the Formosans so successful?
The Coptotermes formosanus, scientific name, has supplanted the native subterranean termite Reticulitermes flavipes and pushed it out of town. Formosan nests often have up to 10 million individual insects, while natives rarely have nests larger than 1 million. Native termites must have a direct connection to underground water sources, while Formosans can survive in above-ground nests, in live oak and other trees, or in walls as long as cellulose (wood) and water are present.
A lone Formosaan soldier termite stands out from worker termites after University of Hawaii researchers introduced dyed food…
How did Formosan insecticides survive?
The formosan termites found ways to avoid conventional liquid termiticides, possibly by recognizing their odors. In New Orleans, nests matured in live oaks and other trees for years. Adult nests “learned” to burrow through treated soil on the outside of homes, sacrificing individual workers and bringing in clean dirt to create tunnels to reach wood in walls, causing hundreds of millions of dollars in damage annually .
In the late 1980s, entomologists, led by researchers at Louisiana State University, the University of Florida, and the University of Hawaii, developed new tactics to attack termite colonies: slower-acting termiteicides in liquid and solid forms. Rather than killing individual insects outright, workers carried treated material back to the nest and fed it to the queen, who eventually died, destroying the entire colony.
A Formosan termite infested tree at Block 6600 of Hastings Street in Metairie was uprooted by high winds in early April 2020, damaging…
What’s that stuff in a Formosan termite nest?
Their nests are built from frass, the scientific name for their droppings, cast in a building material. The termites can store water in some “rooms” of frass, and use other areas for nursery and food storage. The material protects against other insects and wind.
What if I think my house is infested?
First, finding termites crawling around after a heavy swarm doesn’t mean your home is infested. In most cases, these insects have crawled through cracks in windows or door frames to get inside. Just smash them as best you can. Most of them will dry out and die before they can find a way into your walls.
If the termites actually crawl out of a hole in your wall, you could be in trouble. Call a qualified pest control company, preferably one with an entomologist – an insect doctor. They offer to inspect your home, possibly with newer, heat-sensitive devices that could detect a nest in your walls. You may wish to obtain more than one inspection estimate to compare prices. Make sure any agreement you sign has clear language outlining warranties for re-treatment or repair if treatments don’t work.
Even if you don’t think your home is infested, this is a good time to check for telltale signs of termite colonies yourself, including pillars of earth on foundations leading from the ground to a hole between bricks or in siding.
See The Times-Picayune’s 1998 series on Formosan termites, “Home Wreckers.”
The Times-Picayune 1998 investigation into how the Formosan termite is devastating the city of New Orleans.