Crazy ants poised to invade Louisiana

Richard Bogren, Hooper-Bui, Linda M.

News Release Distributed 09/17/09

A new invasive insect is threatening to move into Louisiana, according to experts with the LSU AgCenter.

Rasberry crazy ants are lurking in Texas counties adjacent to Louisiana and are poised to invade the state, according to LSU AgCenter entomologist Linda Hooper-Bùi.

First discovered in the United States in southeast Texas by a pest management professional named Tom Raspberry, after whom they’re named, the ants form super colonies that have the potential to displace native ants, Hooper-Bùi said.

“These colonies are extremely large and have many queens,” she said. And although the ants don’t bite or sting, the colonies get so large they can be overwhelming.

The ants don’t follow trails like most domestic ants but move haphazardly in a “crazy” pattern and in large numbers can resemble “a moving carpet,” Hooper-Bùi said.

“They display mass cooperation,” she added. “They swarm and overwhelm defenses of their prey. They’re what we call a nuisance ant. They can form a ‘superhighway’ across kitchen counters and irritate people in their own homes.”

In addition, the entomologist said crazy ants can disrupt behavior of domestic animals as well as wildlife. And they have been known to infiltrate electrical boxes and disrupt power supplies.

“We have anecdotal evidence of them disrupting wildlife,” Hooper-Bùi said, expressing concern with the well-being of ground-nesting and ground-foraging wildlife.

Unlike most other ants, crazy ants don’t tunnel deep into the ground to nest but rather nest in a variety of habitats, such as under objects in the yard and in potted plants, compost piles and even in buildings, Hooper-Bùi said.

“Our biggest concern in Louisiana is people are rebuilding following hurricanes,” she said. “They’re bringing in soil, mulch, sod and plants that could harbor these ants.”

The entomologist also said the ants could travel hidden in vehicles or in bales of hay brought in to feed livestock.

“Because no governments have imposed quarantines, consumers must be vigilant,” Hooper-Bùi said.

Although experts don’t know for sure, the crazy ants appear to be closely related to Caribbean crazy ants. But the rather small brown-to-black-colored ants are difficult to identify, especially if they aren’t in large colonies.

“Identification has to be done by experts,” Hooper-Bùi said.

The entomologist said native ants are important in nutrient cycling, seed dispersion, aerating soil and the general food chain.

“Ants are the cornerstones our ecosystem is built on,” she said.

Hooper-Bùi said beekeepers have evidence that crazy ants may be overwhelming bee hives and killing bee colonies by directly killing bees and also by feeding on honey and nectar.

“They can be highly devastating,” she said of the crazy ants. “We need to study and monitor them so we can learn the best way to suppress them. We have tools and techniques because we have studied other similar species. We have solid integrated pest management techniques we can employ.”

“Super colonies of some ants can cause an ecological meltdown,” Hooper-Bùi warned. “We can lose plant and animal diversity. They have to be monitored so we can catch infestations early.”

She compared the potential problems with Rasberry crazy ants with problems Argentine ants are causing in the Toledo Bend area of Louisiana.

“All of south Louisiana is a tremendously fragile ecosystem because of hurricanes Katrina, Rita, Gustav and Ike,” Hooper-Bùi said. “If we’re not careful, invasive species could be the only ants in town.”

In fact, crazy ants appear to have displaced fire ants in parts of Texas.

“Fire ants are easier to deal with and are less economically damaging,” Hooper-Bùi said. “People in Texas are saying they’d take the fire ants back rather than contend with crazy ants.”

They could be in Louisiana now, but no one knows it yet, she said.

Rick Bogren

9/17/2009 11:15:12 PM
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