Termite trouble in New Orleans

Termites are eating away the city's trees and buildings

New Orleans is bracing itself for the latest swarming of termites, which are thriving thanks to several years of warmer weather. The insects already cost the city $130m a year in damage, and the plague is getting worse. Our Environment Correspondent Robert Pigott went to see the voracious invaders at work.

Harold Bohn is not pleased to be moving out of his house in State Street but he knows that unless it is fumigated the termites will take over.

"At my time of life I wasn't looking for this upheaval. But they tell me it's the only way to save the house," he says.

Termites have huge wood-eating jaws

Look down State Street, shaded by the magnificent oak trees for which New Orleans is famous, and the Bohns' house stands out.

Among the elegant timber houses with their ornate verandas it is conspicuous in a huge orange and green tarpaulin tent.

Lethal gas

Workmen are pinning each sheet together with what look like giant clothes pegs. In the morning, the house will be filled with a deadly gas and the termites should perish.

The tarpaulin tents are cropping up all over town. After almost a decade of warming temperatures and eight years without a frost in winter, the termites are eating with more appetite than ever.

In Finland Avenue, south of the Mississippi which flows through New Orleans in a long sweeping curve, stands one of the buildings for which the termite control people got there too late.

This house has been condemned by termites

Kerry Lindsey works for a pest eradication firm called Terminix. He estimates that the building contains something like 40 million termites.

Inside, the boarded up rooms are haunted by their presence just behind the wallpaper, in the ceilings, floors, everywhere. Lindsey takes a screwdriver to a wall.

"This is a load bearing member", he says, "but as you can see there's little to nothing left. The termites have really had their way".

Giant jaws

A couple of dozen termites appear in the hole he's made in the wall. A creamy white, about the size of small ants, blind but with huge wood eating jaws. Among them are soldiers, redheaded and with even bigger jaws.

In the bathroom a timber over the window which helps support the roof is just a mass of termite nesting material, composed of faeces bound up with saliva, now like dried mud but riddled with little feeding galleries.

Messenger says up to half of New Orleans trees are infested

At Termite Control, a city entomologist, Matt Messenger, is studying the accelerating life cycle of the Formosan termite. As the climate warms they are swarming earlier.

"They swarmed in the second week of January this year", he says. "It is rare but the temperatures were warm - close to 80 degrees Fahrenheit - so they swarmed. They knew the time was right."

It's not only buildings that are suffering. Matt Messenger says up to half of New Orleans trees are thought to be infested to some degree. He has a section through the trunk of a maple tree which has been entirely hollowed out.

"They start at the base, eat the centre of the tree and just keep on moving up inside it", he says. He picks out a branch taken from the top of the same tree.

The middle is eaten away and filled with the same muddy nest material. "Even in some of the top branches 15 to 20 feet up, they've eaten the inside of those limbs."

It costs New Orleans $130m to cope with the destruction wrought by termites, but the warming climate could bring a far more costly disaster.

Tropical diseases

Mosquitoes carrying malaria and dengue fever can thrive in the sub-tropical conditions, and cases of encephalitis are increasing.

Ed Bordes heads the city's Mosquito Control Board. He says the most worrying development is changes in the viruses carried by insects.

"The insects don't change dramatically through one or two degrees", he says, "but the viruses may. That's what we're seeing, the proliferation of these viruses. And we have not had a winter in New Orleans for eight years, and that's hurt us as well."

A permanent summer seems to be settling over New Orleans, and scientists predict still warmer conditions. The fight against tropical insects is likely to become steadily more difficult.