Formosa termites in Nevada? Bad rumor

We've got a hot rumor we'd like to knock down. It goes something like this: Katrina and Rita leveled Louisiana and folks there are bundling up the damaged wood and shipping it our way as garden mulch. It's supposed to be infected with Formosa subterranean termites.


Formosa subterranean termites couldn't live in Northern Nevada outside of a hothouse, controlled environment. Too dry. And besides, neither Home Depot nor Lowe's is importing any mulch from Louisiana. Both stores have strict rules regarding mulch. They know where it comes from and label mulch, which usually comes in plastic bags. The plastic bags would kill the termites anyhow, as mulch can heat to 130 degrees.

Those bags guarantee that any Formosa subterranean termites inside would die from lack of oxygen, among other things.

Additionally, officials in Louisiana have imposed strict quarantines on 12 parishes on shipping any wood debris out of the local area. It's going into landfills, after being fumigated. Louisiana doesn't want to spread its bugs to the rest of the states.

So, bosh.

Bad actors?

So, what's so bad about Formosa termites anyhow? These bugs came to the United States during World War II aboard freighters bringing in goods. They established themselves in Louisiana and other Gulf states and are quite a problem there.

Formosa termites are voracious eaters of cellulose - wood.

They get around most often in old railroad ties and beams from razed homes in the South. They don't travel in mulch. The process of cutting up wood for mulch largely obliterates the termites.

"The bagging process and storage of bagged mulch is normally not conducive to the survival of many insects, including termites due to temperature and humidity fluctuations (both high and low) often over extended periods of time," writes Jeff B. Knight, entomologist with the Nevada Department of Agriculture. "Bulk shipments may present some issues, but again having the right conditions for survival are minimal for this species."

Formosa termites have larger colonies and eat wood faster than native subterranean termites. Once established in a structure, the Formosa termite is more likely than local termites to find a moisture source. They can survive without ground contact. They are more aggressive, attacking living trees and chewing through non-cellulose materials.

There is no easy way to get rid of Formosa termites. Bug sprays are almost useless, and it takes a formidable termite expert to do away with them. But some new products do eliminate the bugs.

What do they look like?

Like white ants, sort of. But not really.

Termite wings are equal in size and are shed shortly after flying; white ants have forewings larger than the rear legs. Termite antenna are straight; ants' are elbowed. Termites have a broad waist, ants narrow. Termites are soft-bodied and light in color; arts are hard and dark.

How do they live?

Formosa termites need external moisture. They start a colony in the ground and dine on nearby structures. Formosa termite colonies are highly organized with castes of reproductives, workers and soldiers.

The reproductives are the king and queen, one to a colony. They live for up to 25 years, and if they die, secondary reproductives take over the egg-laying function.

Worker termites are soft-bodied, creamy white and wingless. They make up the bulk of the colony and do all the work - building the underground nest, searching for food, feeding other termites and taking care of the eggs and young. The workers are the bad actors as they are the termites that eat houses. Formosa termite worker ants look like termites of other species and cannot be used for identification.

Soldiers have a dark and hard head and a pair of large jaws. Their job is to protect the colony in case of an invasion. Because of their specialized mouth parts, they are not able to chew food and must be fed by workers. Soldiers can be used for identification, but it is best to have samples of all three castes and samples of injured wood.

"This insect is a tropical/subtropical insect and has rather specific temperature and moisture requirements for survival and reproduction," said Knight. "In Nevada's case, the biggest limiting factor would be that this insect is not known to occur north of 35 degrees north latitude (this is the southern tip of Nevada). Extremes in heat and low humidity would also limit its ability to survive here. Las Vegas would be very marginal for survival."

"With all these hurdles to overcome I feel the threat of Formosan termites being brought into Nevada from Louisiana in mulch is negligible if not nonexistent," Knight concluded.

"However, in all cases we should always be watchful for this and other material that might be being moved into Nevada in violation of any state or federal quarantine. In the future we should remember that any real threat like this will come through the normal USDA and State Department of Agriculture channels."

Take that, rumor mongers!

• Contact reporter Sam Bauman at or 881-1236.


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