UCI Makes Ants Go Ape by Giving Them B.O.

Times Staff Writer

Hoping to trigger an ant civil war, UC Irvine scientists are experimenting with a colorless potion that makes bosom-buddy arthropods try to decapitate one another.

The research, announced Thursday at a meeting of the American Chemical Society in San Francisco, could help rein in one of the planet’s most troublesome pests: the Argentine ant.

In California, the species has formed a massive supercolony that stretches from San Diego to Sonoma, wreaking havoc on wildlife, citrus crops and countless kitchens.

The glue that unites the ants is their scent, a hydrocarbon-laced secretion that coats their exoskeletons and enables the insects to identify one another as friends. Unlike their South American cousins, whose myriad body odors incite family feuds with millions of casualties, California’s Argentine ants emit a laid-back, surfer dude-type aroma.


But researchers at UCI think they’ve discovered the six-legged insect’s Achilles’ heels.

In a laboratory not far from the bronze statue of UCI’s anteater mascot, biologist Neil Tsutsui and chemist Kenneth Shea recently created a synthetic version of the Californian ant scent, then tweaked the ingredients slightly and transferred the concoction onto ants serving as guinea pigs.

Like cheap cologne, the new scent offended nearly every other ant in the room. One whiff and they began tearing their suddenly strange-smelling comrades to shreds.

“Our preliminary results strongly suggest that by manipulating chemicals on the exoskeleton, we can disrupt the cooperative behavior of these ants and, in essence, trigger civil unrest within these huge colonies,” Shea said.

Even the most peaceful Argentine ant is never far from going ballistic. Each spring, the workers rise up and execute 90% of their nest’s multiple queens, an insect version of the French Revolution.

On the surface, Argentine arthropods don’t look imposing. Compared with some ant species, they are almost microscopic -- like a bonsai tree next to a redwood. But they make up for their size with sheer numbers.

Since 1891, when they immigrated to New Orleans aboard steamships carrying sugar and coffee from South America, the fast-breeding Argentines have overwhelmed native mom-and-pop colonies and upset ecological balances.

Although fire ants have begun making inroads, Argentines remain the most common arthropod in California.


So far, UCI scientists have distilled five synthetic scents and tested them on about 1,200 ants. Reaction to the odors is rated on a scale that ascends from mild-mannered mandible flaring to decapitation.

Eventually, the synthetic ant scents, which are nontoxic to humans, might be converted to a spray or bait that ants carry to their nests, triggering underground Armageddons, Tsutsui said.

But homeowners expecting relief from the persistent pests shouldn’t get their hopes up. Finding the most potent ant rage elixir could take several years, said Miriam Brandt, a postdoctoral researcher on the project.

And even then, the best that anyone can promise is to curb the Argentine population, not decimate it, she said.