Sunday, May 26, 2013

Fire Ants better than Crazy ones

What's worse than fire ants? Crazy ants:

Invasive Crazy Ants Are Displacing Fire Ants, Researchers Find
[...] “When you talk to folks who live in the invaded areas, they tell you they want their fire ants back,” said LeBrun. “Fire ants are in many ways very polite. They live in your yard. They form mounds and stay there, and they only interact with you if you step on their mound.”

LeBrun said that crazy ants, by contrast, “go everywhere.” They invade people’s homes, nest in crawl spaces and walls, become incredibly abundant and damage electrical equipment.

The crazy ants were first discovered in the U.S. in 2002 by a pest control operator in a suburb of Houston, and have since established populations in 21 counties in Texas, 20 counties in Florida, and a few sites in southern Mississippi and southern Louisiana.

In 2012 the species was formally identified as Nylanderia fulva, which is native to northern Argentina and southern Brazil. Frequently referred to as Rasberry crazy ants, these ants recently have been given the official common name “Tawny crazy ants.”

The Tawny crazy ant invasion is the most recent in a series of ant invasions from South America brought on by human movement. The Argentine ant invaded through the port of New Orleans in about 1891. In 1918 the black imported fire ant showed up in Mobile, Ala. Then in the 1930s, the red imported fire ant arrived in the U.S. and began displacing the black fire ant and the Argentine ants.

The UT researchers studied two crazy ant invasion sites on the Texas Gulf Coast and found that in those areas where the Tawny crazy ant population is densest, fire ants were eliminated. Even in regions where the crazy ant population is less dense, fire ant populations were drastically reduced. Other ant species, particularly native species, were also eliminated or diminished.

LeBrun said crazy ants are much harder to control than fire ants. They don’t consume most of the poison baits that kill fire ant mounds, and they don’t have the same kinds of colony boundaries that fire ants do. That means that even if they’re killed in a certain area, the supercolony survives and can swarm back over the area.

“They don’t sting like fire ants do, but aside from that they are much bigger pests,” he said. “There are videos on YouTube of people sweeping out dustpans full of these ants from their bathroom. You have to call pest control operators every three or four months just to keep the infestation under control. It’s very expensive.”

LeBrun said that in northern Argentina and southern Brazil, where the ants are native, populations are likely held in check by other ant species and a variety of natural enemies. In the U.S. there is no such natural control.

Here the crazy ants can attain densities up to 100 times as great as all other ants in the area combined. In the process, they monopolize food sources and starve out other species. LeBrun said the crazy ants, which are omnivorous, may also directly attack and kill other ant and arthropod species.

The overall result is a significant reduction in abundance and biodiversity at the base of the food chain, which is likely to have implications for the ecosystem as a whole. [...]
Yikes. What can be done? The rest of the article talks about ways of slowing the spread of crazy ants, to buy time to find and answer about what to do about them in the long run. See the article for pics and embedded links.

     

2 comments:

MAX Redline said...

Similar, it seems, to the dispersal pattern of Africanized bees. But more problematic.

Chas said...

Yes. I'm wondering how for north they can go (what their tolerance for cold temperatures is).