Foam + fungus = dead termites
Hungry termites can be a homeowner's worst nightmare.
Spraying chemical insecticides is the usual method of getting rid of the wood-chomping pests. But having the chemicals applied can be expensive--especially if the termites are hiding out in hard-to-reach places.
Now, there could be fewer places for the pests to hide, thanks to an invention by Agricultural Research Service scientists. Their invention is a special foam that quickly expands when sprayed into tiny spaces, like those you'd find between the walls of a home or deep inside trees.
In New Orleans, trees are one of the favorite hiding places of the feared Formosan subterranean termite.
Originally from Asia, it is one of the toughest termite species to control. But the foam developed by the ARS scientists has a secret ingredient: a fungus that's really good at making a home--and a meal--of termites.
The fungus's name is Paecilomyces fumosoroseus (Pay-SEA-lo-my-SEES fu-mo-so-RO-see-us). In nature, it sticks to, and spreads inside, termites and certain other insects to feed and multiply.
The attack begins when the insect brushes past tiny fungal pods called spores. After a few days of the fungus growing and feeding inside the termite, the insect dies. Then, new forms of the fungus punch through the dead insect's outer shell to wait for another victim. But don't worry--the fungus isn't a danger to humans, pets, or livestock.
ARS scientists Chris Dunlap, Mark Jackson, and Maureen Wright thought the fungus could offer a new way to control termites that didn't involve spraying chemicals. And by creating a special foam for the fungus, the scientists made sure they could spread its spores right to where termites hide.
Tests in New Orleans' City Park show the fungal foam has helped evict termites from live oaks and other infested trees. Thanks to a fiber optic camera, the scientists could look inside the trees to check for any survivors.
In fact, the scientists could even watch the foam spread after injecting it into termite-infected trees.
"You could see the termites running, with the foam coming in behind them," says Dunlap. He's a chemist who helped create the foam with Jackson, a microbiologist, in studies at the ARS National Center for Agricultural Utilization Research in Peoria, Illinois.
"Treatments currently being used on trees and in buildings are largely chemical," says Wright, an entomologist with the ARS Southern Regional Research Center in New Orleans. "Our method is a nice option for consumers who like knowing that the termite treatment being used in their homes or yards is biologically based."